喜歡就充值下載吧，，資源目錄下展示的全都有，，下載后全都有，dwg格式的為CAD圖紙，有疑問咨詢QQ：414951605 或1304139763 Journal of Materials Processing Technology 139 (2003) 8189A Windows-native 3D plastic injection mold design systemL. Kong, J.Y.H. Fuh, K.S. Lee, X.L. Liu, L.S. Ling, Y.F. Zhang, A.Y.C. NeeDepartment of Mechanical Engineering, National University of Singapore,10 Kent Ridge Crescent, Singapore 119260, SingaporeAbstract3D solid-modeling revolution has reached the design mainstream. While high-end 3D solid-modeling systems have been on engineersworkstation at large aerospace, consumer products, and automobile companies for years, many smaller companies are now making theswitch from workstations to PC. One reason for the shift is that the flexibility and advancement of Windows-native/NT has let softwaredevelopers create applications that are affordable and easy to use. High-end users are finding that mid-range solid modelers, such asSolidWorks, have met their needs.SolidWorks was chosen as the platform due to the Windows-native design environment, powerful assembly capabilities, ease-of-use,rapid learning curve, and affordable price. A Windows-native 3D plastic injection mold designs system has been implemented on an NTthrough interfacing Visual C+ codes with the commercial software, SolidWorks 99 and API. The system provides a designer with aninteractive computer-aided design environment, which can both speed up the mold design process and facilitate standardization. 2003 Elsevier Science B.V. All rights reserved.Keywords: Plastic injection mold; Windows; CAD; Parting1. IntroductionWith the broader use of plastics parts in a wide productrange, from consumer products to machinery, cars and air-planes, the injection molding process has been recognizedas an important manufacturing process. The mold designprocess is generally the critical path of a new product de-velopment. Conventionally, mold design has always been amuch “mystified” art, requiring years of experience beforeone can be relatively proficient in it. Due to the initial diffi-culty in learning this art, less and less people are benefitingfrom the experience and knowledge of the experts in thisfield. To change the current situation, one way is to use acomputer-aided design (CAD) system.CAD as an everyday term has grown to a broad range ofcapabilities and has applications in fields ranging from edu-cation for school teaching to three-dimensional mechanicaldesign. At the present time, most CAD systems provideonly the geometric modeling functions that facilitate thedrafting operations of mold design, and do not providemold designers with the necessary knowledge to design themolds. Thus, much “add-on” software, e.g. IMOLD, havebeen developed on high-level 3D modeling platforms toCorresponding author. Fax: +65-67791459.E-mail address: mpefuhyhnus.edu.sg (J.Y.H. Fuh).facilitate the mold design processes. Such an arrangementis advantageous in many ways. The 3D modeling platformprovides plug-in software with a library of functions as wellas an established user interface and style of programming.As a result, the development time for these “add-ons” issignificantly reduced.IMOLD(intelligent mold design) 1 is a knowledge-based software application, which runs on the UnigraphicsSolidWorks platform and is carried out by using the UserFunction provided. It is available on the UNIX and windowsoperation system. For years, mold design engineers havehad to deal with two different systems, UNIX and PC. Theformer is widely used in engineering applications whilstthe latter is used mainly in small and medium companies.Engineers also need to run corporate office applications suchas word processing, spreadsheets, and project managementtools, but these were not on their UNIX workstations.Fortunately, the remarkable development of computertechnology in the last decade has provided a way to changethis situation. The most significant change has been inthe area of computer hardware, i.e. the actual electroniccomponents associated with data processing, informationstorage, and display technology, in terms of both speedand memory. These have resulted in the more efficient useof the solid-modeling functions in a PC-based CAD/CAMsystem. With the increased availability of sophisticated,low-cost software for Windows, more and more engineers0924-0136/03/$ see front matter 2003 Elsevier Science B.V. All rights reserved.doi:10.1016/S0924-0136(03)00186-982L. Kong et al./Journal of Materials Processing Technology 139 (2003) 8189are using PC applications to get their jobs done. Thus thedevelopment of a new mold design application based on theWindows platforms is in high demand.High-end users are finding that mid-range solid modelers,such as SolidWorks, have met their needs. Developed fromthe beginning as a native Windows application, SolidWorksis one of the 3D mechanical design softwares for Win-dows. Its unique combination of production-level power,ease-of-use, and affordability is unmatched. SolidWorks99, the seventh major release of the companys mechan-ical design software for Windows NT, Windows 98 andbeyond provides an increased power and functionality in afully integrated solid modeler. Familiar conventions such aspoint-and-click, drag-and-drop, cut-and-paste, and seamlessdata sharing with other Windows software lead to produc-tivity gains. The ease-of-use without extensive training andat affordable pricing enables companies to install the sys-tem on every engineers desktop. One of its applications isfor mold design in the plastics industry. This latest appli-cation technology has added an entirely new dimension tothe mold design process.2. Injection mold designInjection molding uses temperature-dependent changes inmaterial properties to obtain the final shapes of discreteparts to finish or near-finish dimensions through the use ofmolds. In this type of manufacturing process, liquid materialis forced to fill and solidify inside the cavity of the mold 2.Firstly, the creation of a mold model requires a designmodel and a containing box. The design model representsthe finished product, whereas the containing box representsthe overall volume of the mold components.Fig. 1. Relationship among user applications, SolidWorks, Unigraphics and Parasolid.Injectionmolddesigninvolvesextensiveempiricalknowl-edge (heuristic knowledge) about the structure and the func-tions of the components of the mold. The typical processof a new mold development can be organized into four ma-jor phases: product design, moldability assessment, detailedpart design, insert/cavity design, and detailed mold design.In Phase 0, a product concept is pulled together by afew people (usually a combination of marketing and engi-neering). The primary focus of Phase 0 is to analyze themarket opportunity and strategic fit. In Phase I the typicalprocess-related manufacturing information is then addedto the design to produce a detailed geometry. The concep-tual design is transformed into a manufacturable one byusing appropriate manufacturing information. In Phase IIthe parting direction and parting lines location are added toinspect the moldability. Otherwise, the part shape is againmodified. In Phase III, the part geometry is used to establishthe shape of the mold core and cavity that will be used toform the part. Generally shrinkage and expansions need tobe considered so that the molding will be the correct sizeand shape at the processing temperature. Gates, runners,overflows, and vents also need to be added. The associationbetween geometric data and parting information is criticalat this point. Phase IV is related to the overall mechanicalstructure of the mold including the connection of the moldto the injection machine, a mechanisms for filling, cooling,and for ejection and mold assembly.3. MethodologyFor the reasons described above, SolidWorks 99 has beenused as the platform for the new mold design application.Fig. 1 shows a Windows-native 3D injection mold designL. Kong et al./Journal of Materials Processing Technology 139 (2003) 818983system compared with IMOLD. Users applications can becreated and run as a standalone exe file or as a User DLLor Extension DLL in SolidWorks. The SolidWorks Add-InManager allows users to control which third party softwareis loaded at any time during their SolidWorks session. Morethan one package can be loaded at once, and the settingswill be maintained across SolidWorks sessions.3.1. SolidWorksSolidWorksrecentlyemergedasoneofthe3Dproductde-sign software for Windows, providing one of the most pow-erful and intuitive mechanical design solution in its class. InSolidWorks, parts are created by building a “base feature,”and adding other features such as bosses, cuts, holes, fil-lets, or shells. The base feature may be an extrusion, revo-lution, swept profile, or loft. To create a base feature, sketcha two-dimensional geometric profile and move the profilethrough space to create a volume. Geometry can be sketchedon construction planes or on planar surfaces of parts.Feature-basedsolid-modelingprogramsaremakingtwo-dimensional design techniques obsolete. However,Unix-based solid-modeling software are expensive. Withthe introduction of SolidWorks for Microsoft Windows,the cost is less than the price of earlier dimension drivensolid-modeling programs 3.3.2. Parasolid as a 3D kernelSolidWorks uses Parasolid as a 3D kernel. Parasolid ker-nel modeling toolkit, is recognized as a worlds leading,production-proven core solid modeler. Designed as an exactFig. 2. SolidWorks API objects.boundary-representation solid modeler, Parasolid providesrobust solid-modeling, generalized cellular modeling and in-tegrated surface/sheet modeling capabilities and is designedfor easy integration into CAD/CAM/CAE systems to giverapid time to market. Its extensive functionality is suppliedas a library of routines with an object-oriented program-ming interface. It is essentially a solid modeler, which canbe used to 4: (i) build and manipulate solid objects; (ii)calculate mass and moments of inertia, and perform inter-ference detection; (iii) output the objects in various picto-rial ways; (iv) store the objects in some sort of database orarchive and retrieve them later; and (iv) support freeformsurfaces.3.3. API 5The SolidWorks application programming interface (API)is an OLE programming interface to SolidWorks. The APIcontainshundredsoffunctionsthatcanbecalledfromVisualBasic, VBA (Excel, Access, etc.), C, C+, or SolidWorksmacro files. These functions provide the programmer withdirect access to SolidWorks functionality such as creatinga line, extruding a boss, or verifying the parameters of asurface.The API interface uses an object-oriented approach. Allthe API functions are methods or properties that apply to anobject. Fig. 2 is one particular view of the SolidWorks APIobjects.SolidWorks exposes functionality through OLE automa-tion using Dispatch and also through standard COM objects.The Dispatch interface 6 will package arguments and re-turn values as Variants so that languages such as Basic can84L. Kong et al./Journal of Materials Processing Technology 139 (2003) 8189handle them. A COM implementation gives your applica-tion more direct access to the underlying objects, and sub-sequently, increased performance.4. ImplementationsThe facts that SolidWorks API interface uses an object-oriented approach and the API functions allows one toFig. 3. System infrastructure for the mold design application.choose an object-oriented language, e.g. Visual C+, asthe programming language. Using this methodology, aWindows-based 3D injection mold design application is de-veloped on Windows NT through interfacing of the VisualC+ code with a commercial software, SolidWorks 99. Inthis application the mold design process is divided into sev-eral stages, providing the mold designer with a consistentmethod of creating the mold design. The overview of thisframework is shown in Fig. 3. Each stage can be consideredL. Kong et al./Journal of Materials Processing Technology 139 (2003) 818985as an independent module of the program. Several moduleshave been successfully developed using SolidWorks. Twoof them, mold base module and parting module are shownbelow.4.1. Mold base moduleThe mold base module can automatically create parame-tric standard mold bases, with all its components andaccessories, like HASCO, DME, HOPPT, LKM andFUTABA. This module allows easy customization ofmold bases commonly used by designers. Key features in-clude availability of standard mold base components likesupport pillars and sprue bushings, 2-plate and 3-platemold bases, and customization of non-standard moldbases.The mold base module consists of four main sections,namely, the component library (including standard andnon-standard part library), the design table, the dimensiondriven functionality, and structure relation management.Here, the dimension driven functionality is provided bySolidWorks to support for the application. The details forthe mold base module are shown in Fig. 4.(1) Component libraryIn order to strengthen the mold design capability inthis increasingly competitive world, lowering the designcost and cycle time, reducing the man-power, and au-tomation are major factors in achieving this purpose. Inother words, it is necessary to have computer softwarethat is able to easily create, modify, and analyze themold design components, and update the changes in adesign model. To achieve this, a 3D component libraryis provided to store standard and non-standard partsdata, whose dimensions are stored in Microsoft Excel.By specifying the appropriate dimensions, these com-ponents can be generated and inserted into the assemblystructure. This library is completely customizable anddesigners are able to add their own parts into the library.(2) Dimension drivenSolidWorks provides strong dimension driven func-tionality to support parametric design. It is the logi-cal relationship between the dimension sets stored inMicrosoft Excel and the geometry. When a set of di-mension is integrated with the corresponding parameterset of the geometry of an object, the exact model canbe then obtained.(3) Design tableA design table allows a designer to build multipleconfigurations of parts by specifying parameters in anembedded Microsoft Excel spreadsheet. The designtable is saved in the part file and is used to store thedimensions, the suppression of features and the con-figuration properties, including part number in a billof materials, comments, and customer requirements.When appropriate dimensions are added, the designFig. 4. Details of the mold base module.table will contain all the information needed to createan accurate model of the assembly.(4) Structure relation managementThis section records the structure relations betweenmold base components. When supplied with certainparameter set from the design table, this sub-modulehelps the mold designer to insert these componentsinto the assembly structure, thus a specific mold baseassembly can be automatically generated.4.2. Parting moduleSome of the parting algorithms 710 have been reportedpreviously.Inthisdevelopment,partingmoduleisdevelopedto handle the creation of cores and cavities. It is one of themost important modules in a computer-aided injection molddesign system 11. The creation of a mold model needs tohave a design model, a containing box, and parting surfacesavailable. The design model represents the finished product,whereas the containing box represents the overall volume86L. Kong et al./Journal of Materials Processing Technology 139 (2003) 8189Fig. 5. Parting design module.of the mold components. In order to split the box into thecore and cavity, the design model is first subtracted fromthe box. The parting surfaces are then used to separate thecontaining box into mold halves, often referred as the coreand cavity. When melt plastics is injected into the cavity, thefinished product is formed by the two opposing mold halves.After solidification, both mold halves move away from thepart along the parting directions d and d, respectively. Theactual part is then obtained. Fig. 5 shows the parting designprocess.(1) Determination of the parting directionThe pair of opposite directions along which the coreand cavity open are the parting directions (Fig. 6(a).L. Kong et al./Journal of Materials Processing Technology 139 (2003) 818987Fig. 6. Parting design process: (a) determination of parting direction; (b) generation of patching surfaces; (c) determination of parting lines and extrudingdirections; (d) swept parting surfaces; (e) radiated parting surfaces; (f) creation of containing box; (g) generation of the core and cavity.88L. Kong et al./Journal of Materials Processing Technology 139 (2003) 8189To generate the parting lines, the parting directionshould be determined first. The parting direction in-fluences the orientation of the parting line that de-termines the complexity of the mold. In most cases,partingdirectionsaredeterminedbyconsideringboth geometry and manufacturing issues at the sametime.(2) Recognition and patching the “through” holesWhen there are some through holes in a product, thedesigners must indicate the parting location of the holesand generate the parting surfaces in these holes. Thisis called “patching” in this paper. Surfaces are neededand used to patch the through holes. Because the uppermold and the lower mold are connected at the throughhole, a mold cannot be separated and the core and thecavity cannot be created automatically without patchingthose holes first (see Fig. 6(b).(3) Determination of parting lines and the extrudingdirectionsIn molding, one group of the parts surfaces is moldedby the core, and the other group is molded by the cavity.The parting lines are therefore the intersection betweenthe two groups surfaces molded by the core and cavity.The parting lines are chosen from the largest edge-loopin the surface groups.From the parting lines to the boundary of the coreor cavity block, the extruding direction is the path thatthe parting lines will follow during sweeping. It is per-pendicular to the parting direction but parallel to thesurface normal of the side face of the mold box (seeFig. 6(c).(4) Generation of the parting surfacesThe parting surfaces are the mating surfaces of thecore and cavity. The parting surfaces can be used asthe splitting surfaces to cut a mold into two halves.Two methods can be used to generate the partingsurfaces.Sweep method: The parting surfaces are generatedby extruding the parting lines outwards to the outsideboundary of the core and cavity (see Fig. 6(d).Radiate method: In SolidWorks, the parting sur-faces can also be created by using radiating the partinglines with a specified radiate distance that is largeenough to extend the surface beyond the outsidefaces of the containing box (see radiate surfaces inFig. 6(e).(5) Creation of containing boxA containing box encloses the object and the addi-tional suitable space around its periphery is computed.The size of a containing box is determined based on thedimension of the object, the strength of the mold, andthe molding parameters that can effectively define thesize of the mold assembly (Fig. 6(f).(6) Generation of cores and cavitiesIn order to generate cores and cavities, the containingbox must be split into two separate mold halves. Firstly,the design model is subtracted out from the box. Thus,an empty space is obtained inside the containing box.Then parting surfaces and patching surfaces are used asthe splitting surfaces to separate the containing box intotwo mold halves, the core block and the cavity block.Finally, after simulating the mold opening process andchecking the interference among mold components, themold halves are moved away from the part surfaceswithout any interference along the parting directions dand d, respectively (Fig. 6(g).5. ConclusionsThis paper introduces the basic concept of plastics injec-tion mold design and a methodology of CAD for injectionmold. Through Windows NT platform, the methodology hasbeen implemented on