壓縮包內(nèi)含有CAD圖紙和說明書,均可直接下載獲得文件，所見所得，電腦查看更方便。Q 197216396 或 11970985
CONCURRENT?DESIGN?OF?PLASTICS?INJECTION?MOULDS
Abstract
The?plastic?product?manufacturing?industry?has?been?growing?rapidly?in?recent?years.??One?of?the?most?popular?processes?for?making?plastic?parts?is?injection?moulding.??The?design?of?injection?mould?is?critically?important?to?product?quality??and?efficient?product?processing.
Mould-making?companies,?who?wish?to?maintain?the?competitive?edge,?desire?to?shorten?both?design?and?manufacturing?leading?times?of?the?by?applying?a?systematic?mould?design?process.??The?mould?industry?is?an?important?support?industry?during?the?product?development?process,?serving?as?an?important?link?between?the?product?designer?and?manufacturer.??Product?
development?has?changed?from?the?traditional?serial?process?of?design,?followed?by?manufacture,?to?a?more?organized?concurrent?process?where?design?and?manufacture?are?considered?at?a?very?early?stage?of?design.??The?concept?of?concurrent?engineering?(CE)?is?no?longer?new?and?yet?it?is?still?applicable?and?relevant?in?today’s?manuf?acturing?environment.??Team?working?spirit,
management?involvement,?total?design?process?and?integration?of?IT?tools?are?still?the?essence?of?CE.??The?application?of?The?CE?process?to?the?design?of?an?injection?process?involves?the?simultaneous?consideration?of?plastic?part?design,?mould?design?and?injection?moulding?machine?selection,?production?scheduling?and?cost?as?early?as?possible?in?the?design?stage.?
This?paper?presents?the?basic?structure?of?an?injection?mould?design.?The?basis?of?this?system?arises?from?an?analysis?of?the?injection?mould?design?process?for?mould?design?companies.??This?injection?mould?design?system?covers?both?the?mould?design?process?and?mould?knowledge?management.??Finally?the?principle?of?concurrent?engineering?process?is?outlined?and?then?its?principle?is?applied?to?the?design?of?a?plastic?injection?mould.?
Keywords?:Plastic?injection?mould?design,?Concurrent?engineering,?Computer?aided?engineering,?Moulding?conditions,?Plastic?injection?moulding,?Flow?simulation?
1.?Introduction
Injection?moulds?are?always?expensive?to?make,?unfortunately?without?a?mould?it?can?not?be?possible?ho?have?a?moulded?product.??Every?mould?maker?has?his/her?own?approach?to?design?a?mould?and?there?are?many?different?ways?of?designing?and?building?a?mould.?Surely?one?of?the?most?critical?parameters?to?be?considered?in?the?design?stage?of?the?mould?is?the?number?of?cavities,?methods?of?injection,?types?of?runners,?methods?of?gating,?methods?of?ejection,?capacity?and?features?of?the?injection?moulding?machines.??Mould?cost,?mould?quality?and?cost?of?mould?product?are?inseparable?
In?today’s?completive?environment,?computer?aided?mould?filling?simulation?packages?can?accurately?predict?the?fill?patterns?of?any?part.?This?allows?for?quick?simulations?of?gate?placements?and?helps?finding?the?optimal?location.?Engineers?can?perform?moulding?trials?on?the?computer?before?the?part?design?is?completed.?Process?engineers?can?systematically?predict?a?design?and?process?window,?and?can?obtain?information?about?the?cumulative?effect?of?the?process?variables?that?influence?part?performance,?cost,?and?appearance.
2.?Injection?Moulding
Injection?moulding?is?one?of?the?most?effective?ways?to?bring?out?the?best?in?plastics.?It?is?universally?used?to?make?complex,?finished?parts,?often?in?a?single?step,?economically,?precisely?and?with?little?waste.??Mass?production?of?plastic?parts?mostly?utilizes?moulds.??The?manufacturing?process?and?involving?moulds?must?be?designed?after?passing?through?the?appearance?evaluation?and?the?structure?optimization?of?the?product?design.?Designers?face?a?huge?number?of?options?when?they?create?injection-moulded?components.?Concurrent?engineering?requires?an?engineer?to?consider?the?manufacturing?process?of?the?designed?product?in?the?development?phase.?A?good?design?of?the?product?is?unable?to?go?to?the?market?if?its?manufacturing?process?is?impossible?or?too?expensive.??Integration?of?process?simulation,?rapid?prototyping?and?manufacturing?can?reduce?the?risk?associated?with?moving?from?CAD?to?CAM?and?further?enhance?the?validity?of?the?product?development.
3.?Importance?of?Computer?Aided?Injection?Mould?Design
The?injection?moulding?design?task?can?be?highly?complex.?Computer?Aided?Engineering?(CAE)?analysis?tools?provide?enormous?advantages?of?enabling?design?engineers?to?consider?virtually?and?part,?mould?and?injection?parameters?without?the?real?use?of?any?manufacturing?and?time.?The?possibility?of?trying?alternative?designs?or?concepts?on?the?computer?screen?gives?the?engineers?the?opportunity?to?eliminate?potential?problems?before?beginning?the?real?production.?Moreover,?in?virtual?environment,?designers?can?quickly?and?easily?asses?the?sensitivity?of?specific?moulding?parameters?on?the?quality?and?manufacturability?of?the?final?product.??All?theseCAE?tools?enable?all?these?analysis?to?be?completed?in?a?meter?of?days?or?even?hours,?rather?than?weeks?or?months?needed?for?the?real?experimental??trial?and?error?cycles.??As?CAE?is?used?in?the?early?design?of??part,?mould?and?moulding?parameters,?the?cost?savings?are?substantial?not?only?because?of?best?functioning?part?and?time?savings?but?also?the?shortens?the?time?needed?to?launch?the?product?to?the?market.?
The?need?to?meet?set?tolerances?of?plastic?part?ties?in?to?all?aspects?of?the?moulding?process,?including?part?size?and?shape,?resin?chemical?structure,?the?fillers?used,?mould?cavity?layout,?gating,?mould?cooling?and?the?release?mechanisms?used.??Given?this?complexity,?designers?often?use?computer?design?tools,?such?as?finite?element?analysis?(FEA)?and?mould?filling?analysis?(MFA),?to?reduce?development?time?and?cost.??FEA?determines?strain,?stress?and?deflection?in?a?part?by?dividing?the?structure?into?small?elements?where?these?parameters?can?be?well?defined.?MFAevaluates?gate?position?and?size?to?optimize?resin?flow.??It?also?defines?placement?of?weld?lines,?areas?of?excessive?stress,?and?how?wall?and?rib?thickness?affect?flow.??Other?finite?element?design?tools?include?mould?cooling?analysis?for?temperature?distribution,?and?cycle?time?and?shrinkage?analysis?for?dimensional?control?and?prediction?of?frozen?stress?and?warpage.?
The?CAE?analysis?of?compression?moulded?parts?is?shown?in?Figure?1.?The?analysis?cycle?starts?with?the?creation?of?a?CAD?model?and?a?finite?element?mesh?of?the?mould?cavity.??After?the?injection?conditions?are?specified,?mould?filling,?fiber?orientation,?curing?and?thermal?history,?shrinkage?and?warpage?can?be?simulated.?The?material?properties?calculated?by?the?simulation?can?be?used?to?model?the?structural?behaviour?of?the?part.?If?required,?part?design,?gate?location?andshrinkage?and?warpage?can?be?simulated.?The?material?properties?calculated?by?the?simulation?can?be?used?to?model?the?structural?behaviour?of?the?part.?If?required,?part?design,?gate?location?and?processing?conditions?can?be?modified?in?the?computer?until?an?acceptable?part?is?obtained.?After?the?analysis?is?finished?an?optimized?part?can?be?produced?with?reduced?weldline?(known?also?knitline),?optimized?strength,?controlled?temperatures?and?curing,?minimized?shrinkage?and?warpage.??
Machining?of?the?moulds?was?formerly?done?manually,?with?a?toolmaker?checking?each?cut.?This?process?became?more?automated?with?the?growth?and?widespread?use?of?computer?numerically?controlled?or?CNC?machining?centres.?Setup?time?has?also?been?significantly?reduced?through?the?use?of?special?software?capable?of?generating?cutter?paths?directly?from?a?CAD?data?file.?Spindle?speeds?as?high?as?100,000?rpm?provide?further?advances?in?high?speed?machining.??Cutting?materials?have?demonstrated?phenomenal?performance?without?the?use?of?any?cutting/coolant?fluid?whatsoever.?As?a?result,?the?process?of?machining?complex?cores?and?cavities?has?been?accelerated.?It?is?good?news?that?the?time?it?takes?to?generate??a?mould?is?constantly?being?reduced.?The?bad?news,?on?the?other?hand,?is?that?even?with?all?these?advances,?designing?and?manufacturing?of?the?mould?can?still?take?a?long?time?and?can?be?extremely?expensive.?
Many?company?executives?now?realize?how?vital?it?is?to?deploy?new?products?to?market?rapidly.?New?products?are?the?key?to?corporate?prosperity.?They?drive?corporate?revenues,?market?shares,?bottom?lines?and?share?prices.?A?company?able?to?launch?good?quality?products?with?reasonable?prices?ahead?of?their?competition?not?only?realizes?100%?of?the?market?before?rival?products?arrive?but?also?tends?to?maintain?a?dominant?position?for?a?few?years?even?after?competitive?products?have?finally?been?announced?(Smith,?1991).?For?most?products,?these?two?advantages?are?dramatic.??Rapid?product?development?is?now?a?key?aspect?of?competitive?success.?Figure?2?shows?that?only?3–7%?of?the?product?mix?from?the?average?industrial?or?electronics?company?is?less?than?5?years?old.??For?companies?in?the?top?quartile,?the?number?increases?to?15–25%.??For?world-class?firms,it?is?60–80%?(Thompson,?1996).??The?best?companies?continuously?develop?new?products.??At?Hewlett-Packard,?over?80%?of?the?profits?result?from?products?less?than?2?years?old!?(Neel,?1997)?
Figure??1??Importance?of?new?product?(Jacobs,?2000)
With?the?advances?in?computer?technology?and?artificial?intelligence,?efforts?have?been?directed?to?reduce?the?cost?and?lead?time?in?the?design?and?manufacture?of?an?injection?mould.?Injection?mould?design?has?been?the?main?area?of?interest?since?it?is?a?complex?process?involving?several?sub-designs?related?to?various?components?of??the?mould,?each?requiring?expert?knowledge?and?experience.??Lee?et.?al.?(1997)?proposed?a?systematic?methodology?and?knowledge?base?for?injection?mould?design?in?a?concurrent?engineering?environment.?
4.?Concurrent?Engineering?in?Mould?Design?
Concurrent?Engineering?(CE)?is?a?systematic?approach?to?integrated?product?development?process.??It?represents?team?values?of?co-operation,?trust?and?sharing?in?such?a?manner?that?decision?making?is?by?consensus,?involving?all?per?spectives?in?parallel,?from?the?very?beginning?of?the?product?life-cycle?(Evans,?1998).??Essentially,?CE?provides?a?collaborative,?co-operative,?collective?and?simultaneous?engineering?working?environment.??A?concurrent?engineering?approach?is?based?on?five?key?elements:?
（1）.?process
（2）.?multidisciplinary?team
（3）.??integrated?design?model
（4）.?facility
（5）.?software?infrastructure?
Figure?2Methodologies?in?plastic?injection?mould?design,?a)?Serial?engineering?b)?Concurrent?engineering
In?the?plastics?and?mould?industry,?CE?is?very?important?due?to?the?high?cost?tooling?and?long?lead?times.?Typically,?CE?is?utilized?by?manufacturing?prototype?tooling?early?in?the?design?phase?to?analyze?and?adjust?the?design.?Production?tooling?is?manufactured?as?the?final?step.?The?manufacturing?process?and?involving?moulds?must?be?designed?after?passing?through?the?appearance?evaluation?and?the?structure?optimization?of?the?product?design.?CE?requires?an?engineer?to?consider?the?manufacturing?process?of?the?designed?product?in?the?development?phase.?A?good?design?of?the?product?is?unable?to?go?to?the?market?if?its?manufacturing?process?is?impossible.?Integration?of?process?simulation?and?rapid?prototyping?and?manufacturing?can?reducethe?risk?associated?with?moving?from?CAD?to?CAM?and?further?enhance?the?validity?of?the?
?
product?development.?
For?years,?designers?have?been?restricted?in?what??they?can?produce?as?they?generally?have?to?design?for?manufacture?(DFM)?–?that?is,?adjust?their?design?intent?to?enable?the?component?(or?assembly)?to?be?manufactured?using?a?particular?process?or?processes.??In?addition,?if?a?mould?is?used?to?produce?an?item,?there?are?therefore?automatically?inherent?restrictions?to?the?design?imposed?at?the?very?beginning.??Taking?injection?moulding?as?an?example,?in?order?to?process?a?component?successfully,?at?a?minimum,?the?following?design?elements?need?to?be?taken?into?account:?
（1）?geometry;?
? ?draft?angles,??
?Non?re-entrants?shapes,?
? ? near?constant?wall?thickness,
?? complexity,??
?split?line?location,?and??
surface?finish,?
?（2）material?choice;
（3）?rationalisation?of?components?(reducing?assemblies);
（4）.cost.
In?injection?moulding,?the?manufacture?of?the?mould?to?produce?the?injection-moulded?components?is?usually?the?longest?part?of?the?product?development?process.??When?utilising?rapid?modelling,?the?CAD?takes?the?longer?time?and?therefore?becomes?the?bottleneck.??The?process?design?and?injection?moulding?of?plastics?involves?rather?complicated?and?time?consuming?activities?including?part?design,?mould?design,?injection?moulding?machine?selection,?production?scheduling,?tooling?and?cost?estimation.??Traditionally?all?these?activities?are?done?by?part?designers?and?mould?making?personnel?in?a?sequential?manner?after?completing?injection?moulded?plastic?part?design.??Obviously?these?sequential?stages?could?lead?to?long?product?development?time.??However?with?the?implementation?of?concurrent?engineering?process?in?the?all?parameters?effecting?product?design,?mould?design,?machine?selection,?production?scheduling,?tooling?and?processing?cost?are?considered?as?early?as?possible?in?the?design?of?the?plastic?part.??When?used?effectively,?CAE?methods?provide?enormous?cost?and?time?savings?for?the?part?design?and?manufacturing.??These?tools?allow?engineers?to?virtually?test?how?the?part?will?be?processed?and?how?it?performs?during?its?normal?operating?life.?The?material?supplier,?designer,?moulder?and?manufacturer?should?apply?these?tools?concurrently?early?in?the?design?stage?of?the?plastic?parts?in?order?to?exploit?the?cost?benefit?of?CAE.?CAE?makes?it?possible?to?replace?traditional,?sequential?decision-making?procedures?with?a?concurrent?design?process,?in?which?all?parties?can?interact?and?share?information,?Figure?3.?For?plastic?injection?moulding,?CAE?and?related?design?data?provide?an?integrated?environment?that?facilitates?concurrent?engineering?for?the?design?and?manufacture?of?the?part?and?mould,?as?well?as?material?selection?and?simulation?of?optimal?process?control?parameters.
Qualitative?expense?comparison?associated?with?the?part?design?changes?is?shown?in?Figure?4?,?showing?the?fact?that?when?design?changes?are?done?at?an?early?stages?on?the?computer?screen,?the?cost?associated?with?is?an?order?of?10.000?times?lower?than?that?if?the?part?is?in?production.?These?modifications?in?plastic?parts?could?arise?fr?om?mould?modifications,?such?as?gate?location,?thickness?changes,?production?delays,?quality?costs,?machine?setup?times,?or?design?change?in?plastic?parts.
Figure?3??Cost?of?design?changes?during?part?product?development?cycle?(Rios?et.al,?2001)
At?the?early?design?stage,?part?designers?and?moulders?have?to?finalise?part?design?based?on?their?experiences?with?similar?parts.?However?as?the?parts?become?more?complex,?it?gets?rather?difficult?to?predict?processing?and?part?performance?without?the?use?of?CAE?tools.?Thus?for?even?relatively?complex?parts,?the?use?of?CAE?tools?to?prevent?the?late?and?expensive?design?changesand?problems?that?can?arise?during?and?after?injection.?For?the?successful?implementation?of?concurrent?engineering,?there?must?be?buy-in?from?everyone?involved.
5.?Case?Study
Figure?5?shows?the?initial?CAD?design?of?plastics?part?used?for?the?sprinkler?irrigation?hydrant?leg.??One?of?the?essential?features?of?the?part?is?that?the?part?has?to?remain?flat?after?injection;?any?warping?during?the?injection?causes?operating?problems.??
Another?important?feature?the?plastic?part?has?to?have?is?a?high?bending?stiffness.?A?number?of?feeders?in?different?orientation?were?added?to?the?part?as?shown?in?Figure?5b.?These?feeders??should?be?designed?in?a?way?that?it?has?to?contribute?the?weight?of?the?part?as?minimum?as?possible.?
Before?the?design?of?the?mould,?the?flow?analysis?of?the?plastic?part?was?carried?out?with?Moldflow?software?to?enable?the?selection?of?the?best?gate?location?Figure??6a.??The?figure?indicates?that?the?best?point?for?the?gate?location?is?the?middle?feeder?at?the?centre?of?the?part.??As?the?distortion?and?warpage?of?the?part?after?injection?was?vital?from?the?functionality?point?of?view?and?it?has?to?be?kept?at?a?minimum?level,?the?same?software?was?also?utilised?to?yiled?the?warpage?analysis.?Figure?5?b?shows?the?results?implying?the?fact?that?the?warpage?well?after?injection?remains?within?the?predefined?dimensional?tolerances.?
6.?Conclusions??
In?the?plastic?injection?moulding,?the?CAD?model?of?the?plastic?part?obtained?from?commercial?3D?programs?could?be?used?for?the?part?performance?and?injection?process?analyses.?With?the?aid?of?CEA?technology?and?the?use?of?concurrent?engineering?methodology,?not?only?the?injection?mould?can?be?designed?and?manufactured?in?a?very?short?of?period?of?time?with?a?minimised?cost?but?also?all?potential?problems?which?may?arise?from?part?design,?mould?design?and?processing?parameters?could?be?eliminated?at?the?very?beginning?of?the?mould?design.?These?two?tools?help?part?designers?and?mould?makers?to?develop?a?good?product?with?a?better?delivery?and?faster?tooling?with?less?time?and?money.
塑料注塑模具并行設(shè)計(jì)
摘要
塑料制品制造業(yè)近年迅速成長。其中最受歡迎的制作過程是注塑塑料零件。注塑模具的設(shè)計(jì)對產(chǎn)品質(zhì)量和效率的產(chǎn)品加工非常重要。模具公司想保持競爭優(yōu)勢,就必須縮短模具設(shè)計(jì)和制造的周期。
模具是工業(yè)的一個(gè)重要支持行業(yè)，在產(chǎn)品開發(fā)過程中作為一個(gè)重要產(chǎn)品設(shè)計(jì)師和制造商之間的聯(lián)系。產(chǎn)品開發(fā)經(jīng)歷了從傳統(tǒng)的串行開發(fā)設(shè)計(jì)制造到有組織的并行設(shè)計(jì)和制造過程中,被認(rèn)為是在非常早期的階段的設(shè)計(jì)。并行工程的概念(CE)不再是新的,但它仍然是適用于當(dāng)今的相關(guān)環(huán)境。團(tuán)隊(duì)合作精神、管理參與、總體設(shè)計(jì)過程和整合IT工具仍然是并行工程的本質(zhì)。CE過程的應(yīng)用設(shè)計(jì)的注射過程包括同時(shí)考慮塑件設(shè)計(jì)、模具設(shè)計(jì)和注塑成型機(jī)的選擇、生產(chǎn)調(diào)度和成本中盡快設(shè)計(jì)階段。
介紹了注射模具的基本結(jié)構(gòu)設(shè)計(jì)。在該系統(tǒng)的基礎(chǔ)上,模具設(shè)計(jì)公司分析注塑模具設(shè)計(jì)過程。該注射模設(shè)計(jì)系統(tǒng)包括模具設(shè)計(jì)過程及模具知識(shí)管理。最后的原則概述了塑料注射模并行工程過程并對其原理應(yīng)用到設(shè)計(jì)。
關(guān)鍵詞:塑料注射模設(shè)計(jì)、并行工程、計(jì)算機(jī)輔助工程、成型條件、塑料注塑、流動(dòng)模擬。
1、簡介
注塑模具總是昂貴的,不幸的是沒有模具就不可能生產(chǎn)模具制品。每一個(gè)模具制造商都他/她自己的方法來設(shè)計(jì)模具,有許多不同的設(shè)計(jì)與建造模具。當(dāng)然最關(guān)鍵的參數(shù)之一,要考慮到模具設(shè)計(jì)階段是大量的計(jì)算、注射的方法,澆注的的方法、研究注射成型機(jī)容量和特點(diǎn)。模具的成本、模具的質(zhì)量和制件質(zhì)量是分不開的?
在針對今天的計(jì)算機(jī)輔助充型模擬軟件包能準(zhǔn)確地預(yù)測任何部分充填模式環(huán)境中。這允許快速模擬實(shí)習(xí),幫助找到模具的最佳位置。工程師可以在電腦上執(zhí)行成型試驗(yàn)前完成零件設(shè)計(jì)。工程師可以預(yù)測過程系統(tǒng)設(shè)計(jì)和加工窗口,并能獲得信息累積所帶來的影響,如部分過程變量影響性能、成本、外觀等。
2、注射成型法?
????注塑成型是最有效的方法之一,將塑料最好的一面呈現(xiàn)。這是普遍用于制造復(fù)雜的制件,優(yōu)點(diǎn)是簡單、經(jīng)濟(jì)、準(zhǔn)確與少浪費(fèi)。塑料零件的批量生產(chǎn)主要采用模具。產(chǎn)品設(shè)計(jì)制造過程包括模具的結(jié)構(gòu)必須經(jīng)過外觀評價(jià)和結(jié)構(gòu)優(yōu)化。當(dāng)設(shè)計(jì)師創(chuàng)造注射模具組件時(shí)，他們面臨一個(gè)巨大的多種選擇，并行工程需要一個(gè)工程師考慮制產(chǎn)品在發(fā)展階段時(shí)的過程設(shè)計(jì)。一個(gè)好的產(chǎn)品設(shè)計(jì)為了滿足市場其制造過程是不可能太貴的。CAD/CAM整合了過程仿真、快速成形制造能減少風(fēng)險(xiǎn),進(jìn)一步提高產(chǎn)品開發(fā)的有效性。
3、注塑模具設(shè)計(jì)重要的計(jì)算機(jī)輔助
注射模具設(shè)計(jì)任務(wù)是相當(dāng)復(fù)雜的。計(jì)算機(jī)輔助工程(CAE)分析工具提供了巨大的優(yōu)勢讓設(shè)計(jì)工程師考慮幾乎所有模具、注塑參數(shù)沒有真正利用的地方。在可能性的設(shè)計(jì)、理念設(shè)計(jì)師，給工程師們機(jī)會(huì)去消除潛在的問題,開始真正的生產(chǎn)。此外,在虛擬環(huán)境中,設(shè)計(jì)師可以快速而方便地評估特定的成型參數(shù)敏感性的質(zhì)量和生產(chǎn)最終產(chǎn)品。所有這些分析工具使所有模具設(shè)計(jì)將在一天甚至數(shù)小時(shí)完成,而不需要幾周或幾個(gè)月來做真正的實(shí)驗(yàn)反復(fù)試驗(yàn)。CAE用于早期設(shè)計(jì)的部分,模具和注塑模具參數(shù)、節(jié)約成本是實(shí)質(zhì)功能不僅是最好的部分,而且還能節(jié)省和縮短開發(fā)產(chǎn)品推向市場的時(shí)間。
在所有方面的成型過程中需要滿足塑料部分設(shè)置的公差,包括零件的尺寸和形狀,樹脂的化學(xué)結(jié)構(gòu)、填料使用,模具型腔布置、澆注、模具冷卻并釋放機(jī)制使用。面對這復(fù)雜性,設(shè)計(jì)師經(jīng)常使用電腦設(shè)計(jì)工具,如有限元分析(FEA)和充型分析(MFA),減少開發(fā)時(shí)間和成本。有限元分析確定部分結(jié)構(gòu)的應(yīng)變、應(yīng)力和撓度,在那里這些參數(shù)可以很好地被定義。沖型分析位置和大小進(jìn)行優(yōu)化樹脂流動(dòng)。它還定義了焊縫的位置、面積過大的壓力,以及如何影響墻壁和肋厚度流動(dòng)。其它有限元分析設(shè)計(jì)工具包括模具冷卻溫度分布,分析周期時(shí)間和收縮為空間控制和預(yù)測凍結(jié)應(yīng)力、翹曲變形等情況。
采用CAE分析部分壓縮模如圖1所示。分析周期始于創(chuàng)造一個(gè)CAD模型和有限元網(wǎng)格的模具腔。在注入條件規(guī)定,充型、纖維取向、固化和熱歷史、收縮和翹曲變形等情況進(jìn)行仿真。該材料的性能計(jì)算模型模擬可用于結(jié)構(gòu)的行為的一部分。如果需要部分設(shè)計(jì)澆口位置及加工條件可以在電腦上修改,直到一個(gè)可接受的零件的表達(dá)式。摘要分析了一個(gè)優(yōu)化完成部分可采用降低weldline(亦即也knitline),優(yōu)化力量、控制溫度和固化、最小收縮和翹曲變形等情況。
模具加工的前身是手工制作,如檢查每一剪機(jī)床維修工。自動(dòng)化的增長和普遍使用的電腦數(shù)值控制或CNC加工中心使這過程變得更加簡便。設(shè)計(jì)的時(shí)間也被大大降低通過使用特殊的軟件能夠產(chǎn)生刀具路徑直接從CAD數(shù)據(jù)文件提取。主軸速度高達(dá)100000每分鐘轉(zhuǎn)速提一步提出了高速加工。切削材料已經(jīng)證明了驚人的表現(xiàn)而不使用任何的剪切/冷卻液,什么都沒有。作為一個(gè)結(jié)果,加工過程復(fù)雜的型心和型腔已經(jīng)加快了。?
????這是一個(gè)好消息,產(chǎn)生一個(gè)模具所花費(fèi)的時(shí)間不斷的被減少。壞消息是,另一方面,甚至所有這些進(jìn)步、設(shè)計(jì)和制造的模具仍然要花很長時(shí)間,是非常昂貴的。
許多公司的經(jīng)理人現(xiàn)在體會(huì)部署新產(chǎn)品推向市場迅速發(fā)展是多么的重要。企業(yè)的繁榮關(guān)鍵在于新產(chǎn)品。他們推動(dòng)企業(yè)的收入、市場份額、底線和股票價(jià)格。一個(gè)公司能夠發(fā)明優(yōu)質(zhì)的產(chǎn)品和合理的價(jià)格領(lǐng)先其競爭不僅實(shí)現(xiàn)了100%的打敗市場競爭對手的產(chǎn)品,但之前到達(dá)也傾向于保持主導(dǎo)地位甚至幾年之后終于宣布競爭產(chǎn)品(史密斯,1991)。對大多數(shù)產(chǎn)品來說,這兩個(gè)優(yōu)勢是戲劇性的?，F(xiàn)在產(chǎn)品快速發(fā)展的一個(gè)關(guān)鍵方面的競爭成功。圖2顯示,只有3?-?7%的產(chǎn)品結(jié)構(gòu)與一般的工業(yè)或電子公司是小于5歲。公司在第一四分位,這個(gè)數(shù)字增加到15?-?25%。一流的公司,它是60?-?80%(湯普森,1996)。最好的公司在不斷開發(fā)新產(chǎn)品。在惠普,
超過80%的利潤結(jié)果從產(chǎn)品小于2歲!(Neel,1997)?
圖1重要的新產(chǎn)品(雅克布,2000)
以先進(jìn)的計(jì)算機(jī)技術(shù)和人工智能,努力已經(jīng)被指向降低成本和交貨時(shí)間在設(shè)計(jì)和制造注塑模具。注塑模具設(shè)計(jì)主要感興趣的地區(qū),因?yàn)樗且粋€(gè)復(fù)雜的過程涉及到很多表面設(shè)計(jì)等各零件的模具,每個(gè)都需要專家的知識(shí)和經(jīng)驗(yàn)。李et.艾爾。(1997)提出了一種系統(tǒng)的方法關(guān)于注塑模具設(shè)計(jì)的知識(shí)庫和并行工程環(huán)境。
4、并行工程在模具設(shè)計(jì)中
并行工程(CE)是一個(gè)系統(tǒng)性的方法來集成產(chǎn)品開發(fā)過程。它代表了團(tuán)隊(duì)合作的價(jià)值觀、信任和分享,以這樣的方式,決策是通過協(xié)商一致,包括視角并聯(lián),從一開始就產(chǎn)品的整個(gè)生命周期(埃文斯,1998)。從本質(zhì)上講,CE提供合作、合作、集體和同步工程的工作環(huán)境。一個(gè)并行工程的方法是基于五個(gè)關(guān)鍵要素：
（1）、過程
（2）、多學(xué)科小組
（3）、綜合設(shè)計(jì)模