插座盖的注塑模具设计【proe和CAD图纸】

插座盖的注塑模具设计【proe和CAD图纸】,proe和CAD图纸,插座,注塑,模具设计,proe,以及,cad,图纸 附录 1附录英文原文Vo l. 44 Issue 4 2004Jour nal of The Inst itution of Engineers, Singapore3D RAPID REALIZATIONOFIN ITIALDESIG NFOR PLASTICINJECTIONMO ULDSABST RACTMa riaL.H. Lowl andK.S. Le ezTo provide an initial design of the mould assembly for customers prior to receiving the fina lproduct CAD data is a prelimina ry work of any final plast ic inject ion mould design.Traditionallyand even up till now, this initia l design is always created using 2D CAD packages.Theinformation used for the initia l design is based on the technical discussion checklist, in whichmost mould makers have their own standards. This technical discussion checklis t is also beingused as a quotation. This paper presents a met hodology of rapid realization of the initia l design in3D solid based on the technical discuss ion checklist, which takes the role of the overa ll standardtemplate. Infor mationare extracted from databases and coupled with the basic information fromcustomer,these information are input into the technical discussion checklist. Rules and heuris ticsare also being used in the initia l mould design. A case study is provided to illustrate the use of thestandard template and to exhibit its real applica tion of rapid realization of the initia l design,forplastic inject ion moulds.INTRODUCTIONThe most established met hod for producing plast ic parts in lar ge quantities is plast icinject ion mould ing. This is a highly cost- effective, precise and competent ma nufactur ing met hod,which can be automated. However, costly tooling and machiner y are needed in thisma nufactur ing process. The design of a plast ic injection mould is an integral part of plast icinject ion mould ing as the quality of the final plast ic part is greatly relia nt on the injection mould.A plastic injection mould is a high precision tooling that is being used to mass produce plast icparts and is by itself an assembly of cavities, mould base and standard components etc. Anexample of a n inject ion mould assembly is shown in Figure 1.36徐州 工 程 学 院 毕 业 设 计 (论文 )Overtheyears,muchresearchworkusingcomputer- aidedtechniqueshadbeendonefromstudying the ver y specific areas of mould design to studying mould design as a whole integratedsystem. Knowledge-based systems such as IMOLD (Lee et al. 1997), ESMOLD (Chin et al.1997), IKMOULD (Mok et al. 2001), etc were developed for injection mould design. Manycommercia l mould design software packages such as IMOLD, UG MoldWizard, R&BMoldWorks, etc are also available today in the market for mould makers. However, the systemsand software packages mentioned above did not consider the initia l design prior to actual moulddesign. These software packages assist in the preparation of the detailed mould design thatincludes the core/cavity creation, cooling and ejection design. As a result, mould designers hardlyused the mould design software packages when they are doing their initial design because thesoftware does not catered for such a design process.There is not much research being done on the initial design of plast ic injection mouldsexcept for Ye et al. (2000) who presented a n algor ithm for the initial design. The researchers firstdeter mine the parting line for the plast ic part followed by the calculation of the number ofcavities required. The cavity layout is created based on the input information of the la yout patter nand the orientation of each cavity. The mould base is loaded automa tically to accommoda te thela yout. The researchers also proposed to use their initia l design as a guide tool for the quotation ofthe mould. However, the research that is being done may not be applicable for most plast icinject ion mould ing industr ies. The calculation of the number of cavities required is mostlydeter mined by the customers who provides the product CAD file and they seldom seek opinion37徐州 工 程 学 院 毕 业 设 计 (论文 )from the mould makers, thus this step could be omitted to save time. Although exter nal undercutsare identified in the product, the research did not consider the standard components that arerequired in producing such undercuts, which in this case, the use of sliders. The research also didnot consider inter nal undercuts where lifters are required. Thus, the quotation derived would notreflect the correct costing of the mould, and thus could be ver y misleading, since the use of thesetypes of standard components can increase the cost of producing such a mould substa ntia lly.Alter natively, the authors (Low et al. 2002) proposed a methodology of standardizing thecavity la yout design system for plastic injection mould such that only standard cavity layouts areused. When only standard layouts are used, their layout configurations easily be stored in adatabase for fast retr ieva l later in the mould design stage. research is being incor porated into therapid realiza tion of the initia l design for plastic injection mould in this paper.There is a need to introduce a faster method of mould design since there are fewer veryexper ienced mould designers and coupled with the fact of todays market dema nds of havingshorter lead-time and higher quality products. This is fulfilled by the introduction ofstandardization into mould design, since the design processes are repeatable for ever y moulddesign project. This paper presents a met hodology of rapid realization of the initia l design in 3Dsolid instead of 2D drawings using standardization method. The initia l design in 3D solid will bebased on the technical discuss ion checklist that acts as the overa ll standard template. Every sub-design such as cavity layout design, gating system, mould base design etc will have its ownrespective standard template. This is to enable timesa vings in the design stage as the fina l moulddesign can be obtained directly by making minute changes to the initia l design.INITI AL DESIGN OF PLASTIC INJECTION MOULDThe customers and the mould designers have to work closely together to obtain a mould thatcould produce what is desired suitably. It would be costly to rectify the errors after the mould isma nufactured completely. Thus the initia l pla nning of how the la yout design of the mould islikely to be is important. A typica l mould design project workflow chart is shown in Figure 2.When the customers have decided to engage a particular mould- maker, the CAD file of theproduct have to be provided to them. However, the mould-maker is always prepared to receivenewer versions of the product CAD file as changes are consta ntly made to it. The downside ofthis is that the lead- time given to complete the mould still rema ins as it is. Thus, the time that waslef t to complete the fina l mould design and ma nufacture the mould becomes shor ter.When the product CAD file is first received, the assigned project engineer or mould designerfills up a technical checklist during their first technical discussion with the customers. Thechecklist records information such as the resin materia l to be used and its shr inkage value, thenumber of cavities required by customers, the gating system, and the mould ing machine to beused, the required type of mould base and other information needed to provide the basis of the38徐州 工 程 学 院 毕 业 设 计 (论文 )initia l design of the mould. Since thischecklist contains most of the basic infor mation, it doublesup as a quotation.This allows customers to decide whether to modify theirproduct CAD file toproduce a simpler mould that ischeaper. After that, the mould designerprepares an initia l designbased on the product CAD file and infor mation in the checklis tTraditionally andeven up tillnow, mould designersare using 2D CAD packagesto createtheinitial design, although 3D CAD packages are readily available. Ironically, moulddesignerswould then use the 3D CAD package only in their fina l mould design. When thisinitial design iscompleted, it will be presented on the next technical discussion. Modifications made to the initia ldesign are nor ma lly done by marking and sketching the changes o n the printed drawing paper.Though there is no fina l product CAD file at this stage, the mould-maker could go ahead topurchase the raw materials and standard components subject to approval of the customers. Afterthe final product CAD file has been received, the mould designer would start the actual moulddesign afresh using the 3D CAD package that they have. This is a time consuming met hod sincethe initia l design is not related to the fina l mould design.THE DESIGN STRUCTUREFigure 3 shows the overa ll structure of the proposed system. In the proposed approach, the39徐州 工 程 学 院 毕 业 设 计 (论文 )standardization method utilizes standard mould designs, which are derived from the informationlisted in the technical discussion checklist. This checklist takes on the role of the overa ll standardtemplate and must be used for every new mould project. The sub- designs will have their owntemplates. Databases are used to record information such as types of standard components, typesof design, geometrical parameters and project data etc. Mould- making industries can easily adoptthe proposed approach since they are able to customize the databases to include their ownstandards. A standard mould design uses only standard components such as the mould bases;ejector pins and other accessories. Standard configuration of cavity la youts, that produces onlythe same products in a bala nced la yout are used in a standard mould design. Calculations used ina standard mould design are based on rules and heuris tics, which can be applied universa lly toany organizations. Rules and heur ist ics make up a n impor tant sector of mould design since theydeter mine if the mould that is designed, is able to fit into the specified moulding machine or beable to mass produce the product without any problems due to bad design. The hierarchicalorganization of the assembly files of a standard mould design should also follow a single mouldassembly structure.Provision had been made in thissystem to present representationsof the core, cavity, slider40headand lifterhead asblocks徐州 工 程 学 院 毕 业 设 计 (论文 )in the initia l design. These blockscanbe editedtotrim to theprofile only when the fina l product CAD filedesign, ejector pins/blades and cooling lineshas been received and confir med. Dur ing the initialare still not included because these depend greatlyon thefinal productCAD file.Since this paper focuseson therapid realization of initia l design,core/cavity parting, profilecreation, addition of ejector pins/bladesand cooling lineswill not bediscussed here. 3D solidswould be used as they have their advantages. The advantages of solidmodeling are bettervisua lization, simplifiedsimulation, improvedproducability, fasterdrawingproduct ion and facilitates an integrated design process.Standardiza tion met hodStandardiza tion met hod involves using standard mould designs, standard components and astandard working met hod of mould design. This mea ns that every mould designer will designmoulds in exact ly the same met hod, use the same design assembly hierarchy tree, and usestandard components from a specified supplier. This allows the different teams involved in themould project to speak the same la nguage. The advantages are as follows: a) Easy follow ing-upof mould project, b)Lower cost and faster deliver y of components and c) Proper mould projectma nagement.DatabasesFour different types of databases are used in this system (Figure 3): a) LibYaYy database isa collection of a ll standard components commonly used by the mould- making industry. b)CoufiguYatiou database is used for a ll standard components and cavity la yout design. All thedifferent configurations are already pre-defined in the 3D solid files and only the requiredconfiguration will be activated. c) PYOject database is a collection of a ll data that is input into thetechnical discussion checklist and sub- designs inter faces, thus enables tracking and retrieval ofinformation that are unique to a particular project. The quantity of the var ious components andtheir types that are to be used in the project are also recorded here, thus enabling an easygeneration of a n initial bill of mater ia ls (BOMs) when desired and d) Geometr ical paYameteYSdatabase is utilized where there is a need to change the geometrical parameters such as distancesbetween different cavities and locations of standard components etc.SYSTEM IMPLEM ENTATIONA prototype of the rapid realization of initial design system for plastic injection mould hasbeen implemented using a PIII PC-compatible as the hardware. This prototype system utilizesSolidWorks 2001 as the CAD software, Microsoft Visual C+ V6.0 as the programming languageand the SolidWorks API in a Windows environment. The rules, heuristics and formulations usedin this prototype system are based on the local mould making industr ies in Singapore.41徐州 工 程 学 院 毕 业 设 计 (论文 )Technical discussion checklist& mould assembly str uct ureBefore the sub- designs are utilized, the overall standardtemplate,Technica l DiscussionChecklist ,mustbe usedfirst(Figure4). Thisenablesthemoulddesign to followastandardmouldassemblystr uct ureusingtheinitialproductCADfile,thebasicinformationandrequirements from customers. It is impor tant to adhere to the same mould assembly str uct ure forevery mould design project within a n organization to ensure ever y mould designer follows thesame working met hods of designing. It also enables other mould designers to be able to locate acertain design of a component easily.The section Project Tracking records down the basic details of the project. In the sectionknown as the Moulding Material, the resin to be used is chosen from the list. The shr inkagevalue of the resin is entered into the space provided so that the initial product CAD file can bescaled accordingly prior to mould design. The section on Moulding Machine Details allowsusers to select the moulding machine to be used. The customers provide this information. Uponselect ing the required machine from the list, it extracts data from the mould ing machine databaseand reflects the releva nt dimensional information onto the appropr iate spaces in the inter face. Ashort extraction of the injection moulding machine database is depicted in Table 1。The section on42徐州 工 程 学 院 毕 业 设 计 (论文 )Mould Information records down information such as the type of cavity la yout and the numberof cavities that is required. All these information in this section will eventually be used in theirown individ ual sub-designs templates where users are able to input more infor mation orto editthecurrentselectionorthegeometr ica l parameters.Thelastsectionrecordsdown themouldmateria lsandthe type ofsurface finishing required. Thisinformation isneeded fortheinitial quotationand theprocurementofmater ia lsforthemouldproject.Finally,enter ing thepersonsnamethat had recorded theinfor mation and the date when the information isrecordedensures that a properproject database.recordiskept. All the infor mation thatisenteredislistedintoa mouldShrinkage factor&core/ca vity creationA representation of the core and arepresentation ofthecavity in the for m ofblocksaresimultaneouslycreatedtoencapsulatethescaledproductCADfile.Adefault- offset valueisapplied to the range box of the scaledpart to givethe approxima te size of the blocks (Figure 5).These values are commonly used by mould designers loca lly and can be edited.Other accessories/secondar y componentsThe secondary components that may need to be selected during the initial mould design aresliders, lifters and special inser ts. Sliders and lifters will be the source of concer n in the la youtassembly level as they pla yed a part in determining the overa ll size of the la yout assembly. Theyare initially categor ized into the general types and are available in three basic sizes: Small (S),Medium (M) and Large (L). The respective sub- design templates for the sliders and lifters are43徐州 工 程 学 院 毕 业 设 计 (论文 )used to place the components to the appropr iate undercuts. They also functions as an inter face toallow users to edit the geometr ica l parameters or configurations of the secondar y components. Asthis is the initial design, ver y accurate positioning is not required but the secondar y componentshave to be at its correct location and orientation.theCavity layoutOnly standard types of cavity la yout are used in thistypes of available la youts are fixed, the differentprototype system (Low et al. 2002). Astypes of layouts can be listed into aconfiguration databasethat enablestherequiredla yout to be activatedin themouldassemblydur ingthemoulddesign.Thisprovidesafastermethodofdesigning.Thedesirednewconfigurationcanbereloadedviathesub-designtemplateforcavity layout.Inaddition,theorientation, the dista nces between cavities, which are known as geometr ica l parametersbe edited through the same inter face.Selection of mould base sizecan alsoThe secondar y components andcavity layout are assembledin thela yout assembly. Theovera ll sizeof thela yout assembly needsto be known in order to select the appropr iate mouldbase size. The systemautoma tically loadsthesma llest possiblemouldbase from theavailableconfigurationsof thespecified model of mouldbase that has been selected.Simulta neously, thesystemhastocheckthecompatibility ofthechosenmouldbasewith thetargetedinject ion44徐州 工 程 学 院 毕 业 设 计 (论文 )mould ing machine that isto be used for mould ing the products. Parameters that are checked arethetie-bardimensions,platen dimensions,mouldheightandma ximumdaylightofmouldingmachine. A representation of the cla mping unit of the chosen inject ion moulding machine can beactivated to allow the user to verify the design visua lly.Gating&r unner designThe standard design of gates and runner are pre-created and store in a librarydatabase.Dependingonthenumberofcavitiesthatareindica tedear lier,theappropr iateconfiguration will be activatedin the initial mould design.In thisprototypesystem,somerulesand heur ist ics are also set for the gating and runner design. The available optionscan be selectedonly after the type of mould base has been chosen since they are dependent on the type of mouldbase.The rules for selection of the gating are:1. For 2-plate mould, types of gating that can be used are a ll but pin- point gat