1、注塑成型智能模具設(shè)計(jì)工具摘要 注塑成型是一個(gè)生產(chǎn)熱塑性塑料制品最流行的制造工藝，而模具設(shè)計(jì)是這個(gè)過程的一個(gè)重要方面。模具設(shè)計(jì)需要專業(yè)的知識(shí)、技能，最重要的是擁有該領(lǐng)域的經(jīng)驗(yàn)。三者缺一不可。生產(chǎn)塑料組件需要選擇恰當(dāng)?shù)哪＞?，如果缺乏其中之一，這種選擇就得在反復(fù)試驗(yàn)的基礎(chǔ)上進(jìn)行。這會(huì)增加生產(chǎn)成本，并造成設(shè)計(jì)上的不一致。 本文介紹了智能模具設(shè)計(jì)工具的發(fā)展。該工具捕獲模具設(shè)計(jì)過程的知識(shí)，并且以符合邏輯的方式將這些知識(shí)反映出來。所獲得的知識(shí)將是確定性的，但模具設(shè)計(jì)過程中的信息是非確定的。一旦開發(fā)了模具設(shè)計(jì)工具，它將指導(dǎo)使用者根據(jù)不同客戶的要求，為其塑料零件選擇合適的模具。 導(dǎo)言 注塑成型工藝過程需要專業(yè)的

2、知識(shí)、技能，最重要的是需要它成功的實(shí)踐經(jīng)驗(yàn)。通常是工藝參數(shù)控制過程的效率。在制造過程中，有效地控制和優(yōu)化這些參數(shù)能實(shí)現(xiàn)一致性，這種一致性會(huì)在零件質(zhì)量和零件成本上表現(xiàn)出來的問題。1 智能化工程模塊注塑成型工藝（IKEM） 基于知識(shí)的智能化工程模塊的注塑成型工藝（IKEM）是一種軟件技術(shù)，它領(lǐng)先于并行工程和 CAD / CAM 系統(tǒng)。它集成工程的設(shè)計(jì)和制造工藝的最新知識(shí)，給用戶各種設(shè)計(jì)方面的指示，通過減少在產(chǎn)品開發(fā)設(shè)計(jì)階段的工程變更，有助于減少一些工時(shí)。該系統(tǒng)將用于注塑設(shè)計(jì)，設(shè)計(jì)迭代和流程整合。目前的過程由許多手工計(jì)算、CAD 圖形結(jié)構(gòu)和從以前項(xiàng)目取得的經(jīng)驗(yàn)三部分組成。一旦工程師完成設(shè)計(jì)，這將是性

3、能評(píng)估。 該 IKEM 項(xiàng)目已分為三大模塊。 1 費(fèi)用估算模塊 2 模具設(shè)計(jì)模塊 3 生產(chǎn)模塊 IKEM 系統(tǒng)有兩種形式輸入。在一個(gè) CAD 模型的形式（Pro/E 文件）下輸入，和在給出的用戶界面形式下輸入。制造商的經(jīng)驗(yàn)水平將決定如何有效地控制工藝參數(shù)。有時(shí)這就導(dǎo)致人為錯(cuò)誤引起的不一致性。還有經(jīng)驗(yàn)不足，時(shí)間、資源短缺和創(chuàng)新的空間不大的情況。通過創(chuàng)造所謂的“智能模型”的問題，工程學(xué)知識(shí)提供了一個(gè)可行的方案去解決所有這樣 用戶輸入形式 模架設(shè)計(jì) 制造 用戶輸出形式 語法分析程 CAD 模型 成本估計(jì)2 智能模具設(shè)計(jì)工具 在它的基本形式中模具設(shè)計(jì)工具是一個(gè)從文本文件中提取輸入的 Visual Ba

4、sic 應(yīng)用程序，這種文本文件包含關(guān)于零件和用戶輸入程序。該文本文件包含來自 Pro/E 的一個(gè)信息文件的零件的幾何解析。輸入是用來估測(cè)模具得尺寸和其它各種特性。 2.1 文獻(xiàn)回顧 模具設(shè)計(jì)的是另一種注塑成型過程的階段，有經(jīng)驗(yàn)的工程師在很大程度上有助于自動(dòng)化進(jìn)程，提高其效率。這個(gè)問題需要注意的是深入研究設(shè)計(jì)模具的時(shí)間。通常情況下，當(dāng)設(shè)計(jì)工程師設(shè)計(jì)模具時(shí)，他們會(huì)參閱表格和標(biāo)準(zhǔn)手冊(cè)，這會(huì)消耗大量的時(shí)間。另外，在標(biāo)準(zhǔn)的CAD 軟件中需要大量的時(shí)間去考慮模具的建模組件。不同的研究人員已經(jīng)解決了縮短用不同的方式來設(shè)計(jì)模具所花費(fèi)的時(shí)間的問題。凱爾奇和詹姆斯采用成組技術(shù)來減少模具設(shè)計(jì)時(shí)間。聚合一類注塑成型件

5、的獨(dú)特的編碼系統(tǒng)和在注射模具中所需的工具已開發(fā)，它可以適用于其它產(chǎn)品生產(chǎn)線。實(shí)施編碼系統(tǒng)的軟件系統(tǒng)也已經(jīng)被開發(fā)。通過獲取在這方面領(lǐng)域的工程師的經(jīng)驗(yàn)和知識(shí)，嘗試直接使模具設(shè)計(jì)過程的自動(dòng)化。并行模具設(shè)計(jì)系統(tǒng)的研究開發(fā)就是這樣的一個(gè)過程，在并行工程環(huán)境中試圖制定一個(gè)系統(tǒng)的注塑模具設(shè)計(jì)流程。他們的研究目標(biāo)是研制一個(gè)有利于并行工程實(shí)踐的模具開發(fā)的進(jìn)程，和研制開發(fā)一個(gè)以知識(shí)為基礎(chǔ)的為注塑模具設(shè)計(jì)提供工藝問題和產(chǎn)品要求的輔助設(shè)計(jì)。通過各種方式獲取關(guān)于模具設(shè)計(jì)過程的確定信息和不確定信息，研究人員一直試圖使模具設(shè)計(jì)流程自動(dòng)化。這個(gè)研究試圖研制開發(fā)一個(gè)獨(dú)特的模具設(shè)計(jì)應(yīng)用程序，它以確定性和不確定性兩種形式獲取信息。

6、2.2 采用的方法為了發(fā)展智能模具設(shè)計(jì)工具，傳統(tǒng)的模具設(shè)計(jì)方法在被研究。應(yīng)用程序開發(fā)人員和設(shè)計(jì)工程師合作設(shè)計(jì)一種特定塑料零件的模具。在此期間，被工程師采納用來選擇模底座的方法正在被地密切關(guān)注和篩選過程的各個(gè)方面，需要他的知識(shí)經(jīng)驗(yàn)來確定。此外，有時(shí)候工程師將參考圖表和手冊(cè)以規(guī)范其甄選過程。這耗費(fèi)時(shí)間的過程，稍后也被記錄在應(yīng)用程序中。系統(tǒng)的闡述依據(jù)輸入和輸出的應(yīng)用程序是下一階段。這涉及到如何定義什么養(yǎng)的模具布局信息是用戶最需要的，也是他輸入最少卻得到相同的輸出。根據(jù)在模具設(shè)計(jì)工作中收集到的信息，由工程師遵循的公約被轉(zhuǎn)化為if - then 規(guī)則。決策表是用來解釋各種可能出現(xiàn)的情況，它們是當(dāng)處理模具

7、設(shè)計(jì)工程中某一特定的方面所提出的。這樣被制定規(guī)則，然后被組織在相互交融的模塊中，使用應(yīng)用程序開發(fā)環(huán)境。最后，應(yīng)用程序是檢驗(yàn)其正確性，當(dāng)涉及到為塑料零件設(shè)計(jì)模具在工業(yè)生產(chǎn)中。2.3 選擇合適的模架通常情況下，為制造塑料零件選擇適當(dāng)?shù)哪＜芩婕暗挠校海?）估計(jì)模腔數(shù) 模腔數(shù)量的決定取決于在一定時(shí)間內(nèi)所需部件的數(shù)量，像機(jī)器的塑化能力，廢品率等問題也會(huì)影響到模架的模腔數(shù)量。（2）確定鑲塊及其尺寸 鑲塊有助于模架重用，因此有助于降低生產(chǎn)成本。當(dāng)涉及到尺寸和數(shù)量的選擇，作出決定取決于現(xiàn)有的鑲塊的重用性和新的鑲塊的成本。（3）確定澆道的尺寸和定位 澆道的尺寸取決于所成型的材料。盡管還有其它要考慮材料特性來決

8、定它的澆道的尺寸供符合它的流量要求。轉(zhuǎn)輪的定位，取決于所用流道的拓?fù)洳季?。雖然循環(huán)的澆道系統(tǒng)始終是最好的，支道系統(tǒng)的平衡，避免流道均衡補(bǔ)償?shù)臉渲顫驳老到y(tǒng)是一個(gè)最被廣泛應(yīng)用的系統(tǒng)。（4）確定澆道直徑 澆道直徑?jīng)Q定于模具的尺寸，模腔的數(shù)量或在一定的時(shí)間內(nèi)用來填補(bǔ)的塑料的總數(shù)。（5）澆口的定位 塑料在某一點(diǎn)進(jìn)入模腔，在這點(diǎn)可以均勻填充滿模腔。澆口可以設(shè)在循環(huán)模腔的任何周圍點(diǎn)，但當(dāng)填補(bǔ)矩形腔時(shí)，必須從中部流進(jìn)。（6）確定供水道的的尺寸和定位 供水道之間和從模具中的任何壁上以標(biāo)準(zhǔn)的距離定位。該公約不是用一個(gè)直徑范圍定位水道在模具壁上。（7）根據(jù)以上結(jié)論確定模具的尺寸 根據(jù)以上的所有結(jié)論，模具的大概尺寸

9、可以被估計(jì)，并四舍五入至最接近的產(chǎn)品目錄號(hào)。在模架以前，如果重新設(shè)計(jì)，考慮到以上所有方面會(huì)降低成本和減少設(shè)計(jì)時(shí)間，進(jìn)入重新設(shè)計(jì)。2.4 問題的提出建立問題，需要人的知識(shí)和經(jīng)驗(yàn)，模具設(shè)計(jì)方面消耗的時(shí)間涉及到圖表，數(shù)據(jù)表等，為開發(fā)應(yīng)用程序的問題解釋。雖然大部分的輸入如模腔數(shù)、腔的圖像尺寸、周期時(shí)間，都是根據(jù)客戶要求，其他輸入如塑化能力、每分鐘注射量等，可從機(jī)器的說明書中獲得。應(yīng)用程序的輸出包含模具尺寸和其他資料，這顯然有助于在目錄中選擇標(biāo)準(zhǔn)模架。Intelligent Mold Design Tool For Plastic Injection MoldingAbstract Plastic In

10、jection molding is one of the most popular manufacturing processes for making thermo plastic products and mold design is a key aspect of the process. Design of molds requires knowledge expertise and most importantly experience in the field. When one of these is lacking selection of an appropriate mo

11、ld for manufacturing a plastic component is done on a trial-and-error basis. This increases the cost of production and introduces inconsistencies in the design. This paper describes the development of an intelligent mold design tool. The tool captures know ledge about the mold design process and rep

12、resents the knowledge in logical fashion. The knowledge acquired will be deterministic and non-deterministic information about the mold design process. Once developed the mold design tool will guide the user in selecting an appropriate mold for his plastic part based on various client specifications

13、. IntroductionThe plastic injection molding process demands knowledge expertise and most important experience for its successful implementation. Often it is the molding parameters that control the efficiency of the process. Effectively controlling and optimizing these parameters during the manufactu

14、ring process can achieve consistency which takes the form of part quality and part cost. The level of experience of the manufacturers determines how effectively the process parameters are controlled. This sometimes leads to inconsistency introduced by human error. There is also the case where there

15、is inexperience shortage of time resources and little scope for innovation. Knowledge-based engineering provides a feasible solution to all these problems by creating what is called an “intelligent model” of the problem. 1 IKEM Intelligent Knowledge based Engineering modules for the plastic injectio

16、n molding process IKEM is a software technology that is a step ahead of the concurrent engineering and CAD/CAM systems. It integrates current knowledge about the design and manufacturing processes and helps to reduce several man-hours by reducing engineering changes in the design phase of product de

17、velopment by giving users instruction about various design aspects. The system will be used for injection molding design design iterations and process integration. The current process consists of many manual computations CAD graphical constructions and experience attained from previous projects. Onc

18、e the engineer completes the design it will be evaluated for performance. The IKEM project has been divided into three major modules. 1. The cost estimation module 2. The mold design module 3. The Manufacturing module Input to the IKEM system is of two forms. Input in the form of a CAD model Pro-E f

19、ile and input given at the User Interface form. The manufacturers level of experience will determine how to effectively control the process parameters. Sometimes this leads to inconsistency caused by human error. There is lack of experience, lack of time, lack of resources and innovative space. Thro

20、ugh the creation of a smart model, engineering knowledge provides a feasible scheme to solve all user input form mold design and manufacture of the user output form of syntax analysis process CAD model cost estimation 2 Intelligent Mold Design Tool The mold design tool in its basic form is a Visual

21、Basic application taking input from a textfile that contains information about the part and a User Input form. The text file containsinformation about the part geometry parsed from a Pro/E information file. The input is used toestimate the dimensions of mold and various other features. 2.1 Literatur

22、e ReviewDesign of molds is another stage of the injection molding process where the experience of an engineer largely helps automate the process and increase its efficiency. The issue thatneeds attention is the time that goes into designing the molds. Often, design engineers refer to tables and stan

23、dard handbooks while designing a mold, which consumes lot of time. Also, a great deal of time goes into modeling components of the mold in standard CAD software. Different researchers have dealt with the issue of reducing the time it takes to design the mold in different ways. Koelsch and James have

24、 employed group technology techniques to reduce the mold design time. A unique coding system that groups a class of injection molded parts, and the tooling required in injection molding is developed which is general and can be applied toother product lines.A software system to implement the coding s

25、ystem has also been developed. Attemptswere also directed towards the automation of the mold design process by capturing experience and knowledge of engineers in the field. The development of a concurrent mold design system is one such approach that attempts to develop a systematic methodology for i

26、njection mold design processes in a concurrent engineering environment. The objective of their research was to develop a mold development process that facilitates concurrent engineering-based practice, and to develop a knowledge-based design aid for injection molding mold design that accommodates ma

27、nufacturability concerns, as well as product requirements.Researchers have been trying to automate the mold design process either by capturing only the deterministic information on the mold design process or the non-deterministic information, in various ways. This research uniquely attempts to devel

28、op a mold design application that captures information in both forms; deterministic and non-deterministic.2.2 Approach AdoptedIn order to develop an intelligent mold design tool, the conventional method of designing molds is studied. The application developer and the design engineer work together in

29、 designing a mold for a particular plastic part. During this time, the approach adopted by the engineer to select the mold base is closely observed and aspects of the selection process that require his knowledge/experience are identified. Also, there will be times when the engineer will refer to tab

30、les and handbooks in order to standardize his selection process. This time consuming process is also recorded to incorporate it later in the application.Formulating the problem for the application in terms of inputs and outputs is the nextstage. This involves defining what information about the mold

31、 layout is most required for the user and also the minimum number of inputs that can be taken from him to give those outputs.Based on the information gathered in the mold design exercise, the conventions followed by the engineer are transformed into if-then rules. Decision tables are used to account

32、 for all possible cases that arise when dealing with a particular aspect of the mold design process. The rules so framed are then organized into modules interacting with each other, using an application development environment. Finally the application is tested for its validity when it comes to desi

33、gning molds for plastic parts manufactured in the industry.2.3 Selection of Appropriate Mold BaseTypically, selection of appropriate mold base for manufacturing a plastic part involvesEstimating the number of cavitiesThe number of cavities is decided depending on the number of parts required within

34、a given time. There are also other issues like the plasticizing capacity of the machine, reject rate etc that affect the number of cavities to be present in the mold base.Deciding on the presence of inserts and their dimensionsInserts facilitate the reusability of the mold base and therefore help in

35、 reducing cost of manufacturing. When it comes to selecting the dimensions and the number, a decision is made depending on the reusability of existing old inserts and cost of ordering new ones.Determining the size and location of runnersThe runner size depends on the material being molded. Although

36、there are other considerations material properties determines the channel size required for its flow. Location of runners mainly depends on the topology of runners being used. Though a circular runner system is always preferable, the branched runner system that avoids runner balancing is the one mos

37、t widely used.Determining the diameter of sprueThe diameter of the sprue is decided based on the size of the mold, number of cavities, or the amount of plastic that is to be filled within a given time.Locating gatesPlastic enters the cavity at a point where it can uniformly fill the cavity. A gate can b