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0附录 4 英文资料及中文翻译3D RAPID REALIZATION OF INITIAL DESIGN FORPLASTIC INJECTION MOULDSMaria L.H. Low1 and K.S. Lee2ABSTRACTTo provide an initial design of the mould assembly for customers prior to receiving the final product CAD data is a preliminary work of any final plastic injection mould design. Traditionally and even up till now, this initial design is always created using 2D CAD packages. The information used for the initial design is based on the technical discussion checklist, in which most mould makers have their own standards. This technical discussion checklist is also being used as a quotation. This paper presents a methodology of rapid realization of the initial design in 3D solid based on the technical discussion checklist, which takes the role of the overall standard template. Information are extracted from databases and coupled with the basic information from customer, these information are input into the technical discussion checklist. Rules and heuristics are also being used in the initial mould design. A case study is provided to illustrate the use of the standard template and to exhibit its real application of rapid realization of the initial design for plastic injection moulds.INTRODUCTIONThe most established method for producing plastic parts in large quantities is plastic injection moulding. This is a highly cost-effective, precise and competent manufacturing method, which can be automated. However, costly tooling and machinery are needed in this manufacturing process. The design of a plastic injection mould is an integral part of plastic injection moulding as the quality of the final plastic part is greatly reliant on the injection mould. A plastic injection mould is a high precision tooling that is being used to mass produce plastic parts and is by itself an assembly of cavities, mould base and standard components etc.Over the years, much research work using computer-aided techniques had been done from studying the very specific areas of mould design to studying mould design as a whole integrated system. Knowledge-based systems such as IMOLD (Lee et al. 11997),ESMOLD (Chin et al. 1997), IKMOULD (Mok et al. 2001), etc were developed for injection mould design. Many commercial mould design software packages such as IMOLD, UG MoldWizard, R&B MoldWorks, etc are also available today in the marketfor mould makers. However, the systems and software packages mentioned above did not consider the initial design prior to actual mould design. These software packages assist in the preparation of the detailed mould design that includes the core/cavity creation, cooling and ejection design. As a result, mould designers hardly used the mould design software packages when they are doing their initial design because the software does not catered for such a design process.There is not much research being done on the initial design of plastic injection moulds except for Ye et al. (2000) who presented an algorithm for the initial design. The researchers first determine the parting line for the plastic part followed by the calculation of the number of cavities required. The cavity layout is created based on the input information of the layout pattern and the orientation of each cavity. The mould base is loaded automatically to accommodate the layout. The researchers also proposed to use their initial design as a guide tool for the quotation of the mould. However, the research that is being done may not be applicable for most plastic injection moulding industries.The calculation of the number of cavities required is mostly determined by the customers who provides the product CAD file and they seldom seek opinion from the mould makers, thus this step could be omitted to save time. Although external undercuts are identified in the product, the research did not consider the standard components that are required in producing such undercuts, which in this case, the use of sliders. The research also did not consider internal undercuts where lifters are required. Thus, the quotation derived would not reflect the correct costing of the mould, and thus could be very misleading, since theuse of these types of standard components can increase the cost of producing such a mould substantially.Alternatively, the authors (Low et al. 2002) proposed a methodology of standardizing the cavity layout design system for plastic injection mould such that only standard cavity layouts are used. When only standard layouts are used, their layout configurations can easily be stored in a database for fast retrieval later in the mould design stage. This research is being incorporated into the rapid realization of the initial design for plastic injection mould in this paper. There is a need to introduce a faster method of mould design since there are fewer very experienced mould designers and 2coupled with the fact of todays market demands of having shorter lead-time and higher quality products. This is fulfilled by the introduction of standardization into mould design, since the design processes are repeatable for every mould design project. This paper presents a methodology of rapid realization of the initial design in 3D solid instead of 2D drawings using standardization method. The initial design in 3D solid will be based on the technical discussion checklist that acts as the overall standard template. Every sub-design such as cavity layout design, gating system, mould base design etc will have its own respective standard template. This is to enable timesavings in the design stage as the final mould design can be obtained directly by making minute changes to the initial design.INITIAL DESIGN OF PLASTIC INJECTION MOULDThe customers and the mould designers have to work closely together to obtain a mould that could produce what is desired suitably. It would be costly to rectify the errors after the mould is manufactured completely. Thus the initial planning of how the layout design of the mould is likely to be is important. A typical 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 the product have to be provided to them. However, the mould-maker is always prepared to receive newer versions of the product CAD file as changes are constantly made to it. The downside of this is that the lead-time given to complete the mould still remains as it is. Thus, the time that was left to complete the final mould design and manufacture the mould becomes shorter.When the product CAD file is first received, the assigned project engineer or mould designer fills up a technical checklist during their first technical discussion with the customers. The checklist records information such as the resin material to be used and its shrinkage value, the number of cavities required by customers, the gating system, and the moulding machine to be used, the required type of mould base and other information needed to provide the basis of the initial design of the mould. Since this checklist contains most of the basic information, it doubles up as a quotation. This allows customers to decide whether to modify their product CAD file to produce a simpler mould that is cheaper. After that, the mould designer prepares an initial design based on the product CAD file and information in the checklist.Traditionally and even up till now, mould designers are using 2D CAD packages to create the initial design, although 3D CAD packages are readily available. Ironically,mould designers would then use the 3D CAD package only in their final mould design. When this initial design is completed, it will be presented on the next technical 3discussion. Modifications made to the initial design are normally done by marking and sketching the changes on the printed drawing paper. Though there is no final product CAD file at this stage, the mould-maker could go ahead to purchase the raw materials and standard components subject to approval of the customers. After the final product CAD file has been received, the mould designer would start the actual mould design a fresh using the 3D CAD package that they have. This is a time consuming method since the initial design is not related to the final mould design.THE DESIGN STRUCTUREIn the proposed approach, the standardization method utilizes standard mould designs, which are derived from the information listed in the technical discussion checklist. This checklist takes on the role of the overall standard template and must be used for every new mould project. The subdesigns will have their own templates. Databases are used to record information such as types of standard components, types of design, geometrical parameters and project data etc. Mould-making industries can easily adopt the proposed approach since they are able to customize the databases to include their own standards. A standard mould design uses only standard components such as the mould bases; ejector pins and other accessories. Standard configuration of cavity layouts, that produces only the same products in a balanced layout are used in a standard mould design. Calculations used in a standard mould design are based on rules and heuristics, which can be applied universally to any organizations. Rules and heuristics make up an important sector of mould design since they determine if the mould that is designed, is able to fit into the specified moulding machine or be able to mass produce the product without any problems due to bad design .The hierarchical organization of the assembly files of a standard mould design should also follow a single mould assembly structure. Provision had been made in this system to present representations of the core, cavity, slider head and lifter head as blocks in the initial design. These blocks can be edited to trim to the profile only when the final product CAD file has been received and confirmed. During the initial design, ejector pins/blades and cooling lines are still not included because these depend greatly on the final product CAD file. Since this paper focuses on the rapid realization of initial design, core/cavity parting, profile creation, addition of ejector pins/blades and cooling lines will not be discussed here. 3D solids would be used as they have their advantages. The advantages of solid modeling are better visualization, simplified simulation, improved producability, faster drawing production and facilitates an integrated design process.4STANDARDIZATION METHODStandardization method involves using standard mould designs, standard components and a standard working method of mould design. This means that every mould designer will design moulds in exactly the same method, use the same design assembly hierarchy tree, and use standard components from a specified supplier. This allows the different teams involved in the mould project to speak the same language. The advantages are as follows: a) Easy following-up of mould project, b) Lower cost and faster delivery of components, c) Proper mould project management.DATABASESFour different types of databases are used in this system: a) Library database is a collection of all standard components commonly used by the mould-making industry. b) Configuration database is used for all standard components and cavity layout design. All the different configurations are already pre-defined in the 3D solid files and only the required configuration will be activated. c) Project database is a collection of all data that is input into the technical discussion checklist and sub-designs interfaces, thus enables tracking and retrieval of information that are unique to a particular project. The quantity of the various components and their types that are to be used in the project are also recorded here, thus enabling an easy generation of an initial bill of materials when desired and d) Geometrical parameters database is utilized where there is a need to change the geometrical parameters such as distances between different cavities and locations of standard components etc.SYSTEM IMPLEMENTATIONA prototype of the rapid realization of initial design system for plastic injection mould has been implemented using a PIII PC-compatible as the hardware. This prototype system utilizes SolidWorks 2001 as the CAD software, Microsoft Visual C+ V6.0 as the programming language and the SolidWorks API in a Windows environment. The rules, heuristics and formulations used in this prototype system are based on the local mould making industries in Singapore.CONCLUSIONSAn approach to using the standardization method is applied to the rapid realization of the initial design of plastic injection moulds in this paper. Design processes that are the same for every mould design project are consolidated into a standard template. The technical discussion checklist takes on the role of the overall standard template while the subdesigns have their own sub-templates. The use of databases allows the flexibility in allowing customization. Approximate costing of the 5mould can also be derived from the information based on the checklist. Other advantages include having a faster approach to design, designing a mould that functions and easy visualization.However, this rapid realization of initial design system has its limitations. As technology advances, more databases, rules and heuristics needs to be built into the system to accommodate for mould designs meant for the newer forms of plastic injection moulding such as multi-colour moulding and thin-wall moulding. Much effort and money needs to be invested by organizations to customize their systems to consider the new technologies. The databases for the materials and moulding machine also had to be constantly updated and checked to account for the newer materials and machines that are introduced into the industry. If there is a wrong entry in the databases, the results that are obtained can be disastrous. An experienced designer would know at once when the design is not right but to a novice designer, he/she may just accept the design without much thought, believing that the system would always provide the correct solution. The authors are currently researching into improving the system so as to enable an easier approach of customization.6初步实现塑胶射出成型模具快速三维设计Maria L.H. Low1 and K.S. Lee2摘要塑料射出成型模具设计的初步任务是提供给客户模具装配设计最终得到产品的 CAD 数据。 传统上,甚至到现在，这种原始设计制造总是用 2 维 CAD 进行组件。用于最初设计的信息是基于技术讨论文件，其中大部分都有模具制造者自己的标准制定模式。 这一技术讨论文件也被用来作为行情表.。本文基于那些起着标准模版作用的技术讨论文件提出了快速实现三维实体初步设计的方法论。摘自数据库的信息加上顾客的基本资料，这些资料都输入技术讨论文件。初期的模具设计中也用到了规律和直观推断。关键研究是图解和展现标准模板在快速实现塑料射出成型模具初期设计的真正应用。简介大量生产塑料零件的最现成的方法就是塑料注模。这是一个极具成本效益、准确的和具有制造能力可以自动化的方法。但是, 这个制造过程需要昂贵的工具和机械。塑料注射模的设计是塑胶成型的重要部分，因为最终的塑料零件质量取决于注射铸模。塑胶铸模注射高精密工具正被用来大规模生产塑料部件。它本身就是一个模槽、基础模具和标准配件的组装。多年来,许多研究利用计算机辅助技术完成特殊模具的设计的学习，以把模具设计作为一个集成系统来研究。 许多系统的科学体系像IMOLD、ESMOLD 、IKMOULD 正用于铸射模具的设计当中。模具制造者同样可以在市场上买到许多商业模具设计软件像 IMOLD，UG MoldWizard，R&B MoldWorks。 但是，上述软件和系统不考虑实际模具的初步设计。这种软件包协助制定详细的模式设计,包括核心、创建、冷却、反应堆设计。 因此，模具设计师做初步设计时很难用软件设计，因为软件设计不照顾这个设计过程。除了 2000 年提出了初步设计的算法之外，对塑胶射出成型模具的初步设计没有太多的研究。因为对槽模数量的累积需求研究人员首次投入了塑料零件的生产线。模槽的布局是通过输入的每个模槽的形式和方向创建的。模具坯子将自动适应布局。研究人员还提出用最初设计为行情做导向工具。 然而,正在进行的研究未必适用于大多数塑胶射出成型浇铸工业。槽模数量的需要是由提供产品的CAD 资料 的客户决定的，他们很少寻求模具制造者的意见，因此这一步骤可以省略以节省时间。尽管外部底切在产品中已被定义，但是在没有考虑到生产这样的底切时所需要的部件标准的情况下，使用滑板。研究也没有考虑到提钩所需的内部底切。所以，推导出的报价表不能正确反映模具的成本，很可能引起误解。因为这类标准组件可以大幅增加生产成本。7另外,作者提出了规范的塑胶射出成型系统可以使槽模布置正规化。只有使用标准设计、布局结构能容易在数据库检索后快速储存。本文中将此研究与塑胶射出成型模具初步设计的快速实现结合起来。要加快引进模式设计方法,因为资深模具设计师很少，加上今天的在较短的准备时间提高产品质量的市场需求。标准化涉入到模具设计当中实现了这个要求，因为每个模具的设计过程是重复的。本文提出了用三维实体标准化方法代替二维的初步图纸设计实现快速的方法。三维实体的初步设计在基于技术文件基础上作为标准模板。每个设计例如模槽布置设计，系统集成，模具坯子设计等都有自己的标准模板。这使得在对初始设计进行几分钟的修改就可以得到最终设计。塑料注射模具的初步设计客户和模具设计师要密切配合,取得最适合的模具。在模具完全加工出来之后纠正错误花费是很大的。因此,如何设计初步规划是重要的。当客户想制造特殊的模具时，要提供零件所有的 CAD 文件。然而, 模具制造者愿意接受产品新的 CAD技术文件因为将不断对模具作出改变。 坏处是，更换模具的时间还是没有改变。因此,现在所剩下的完成最后模具设计和制造的时间也愈来愈短。当第一次收到产品 CAD 文件时，模具设计师通过与顾客的交谈记录了产品的技术要求。记录了如树脂材料及其价值萎缩,系统安装 ,及模具坯子等其他设计模具时所需的信息。因为一览表中包含了最基础的信息, 所以把它作为报价表。这使得客户决定是否修改其产品 CAD 文件制作简单便宜的铸模。之后, 设计师依据产品清单上的 CAD 文件编制初步设计。传统上,甚至到目前为止, 初期设计制造仍使用 2 维 CAD,虽然有现成的三维CAD。 模具设计师只在最后一揽表设计模式利用三维造型设计。 当初步设计完成后, 将它提交到下一个技术性讨论。通常通过修改图纸上的标注和草绘对初步设计进行修改。虽然在这个阶段没有产品最终的 CAD 文件资料，模具制造者经过客户的允许可先采购原料及标准部件。在得到产品的 CAD 文件之后，模具设计师将展开实际的三维设计模式。 这是一项费时的工作,因为初期设计与模具最终设计无关。结构设计规范的设计方法是利用基于技术清单信息的标准模式。这个清单代表模板的整体水平,每个项目必须采用新的模式。每个设计都有自己的模板。数据库是用来记录标准组件的类型、设计类型、立体参数和数据等信息。所提方案适用于模具制造, 因为这些方法能根据自己的标准制定数据库。标准模具设计只使用标准组件如模具底座，起模器等。标准模槽设计布局，通过采用标准模式的均衡布局来生产同类产品。标准模具设计中的计算普遍适用于其它装配。规则及直接推断是模具设计中的重要组成部分,因为造型设计目的是设计出能够适应特定机器或可批量8生产的产品，不会因为不良设计而出现任何问题。标准模式设计只采用单一结构模式。型芯、腔、滑板、钓勾已经作为块存在初期设计中。当最终确定产品 CAD文件后，这些块能够被编辑成剖面图。在初始的设计中，起模钉和冷却管道不包括在内，因为这些模块是从最终的产品 CAD 文件中生成的。从而本论文主要论述初始设计的快速变现，型心和型腔的分界模，加上起模钉与冷却管道将不在此讨论。应用三维实体造型是因为它有自己的优势。实体模型的优点是可视化比较强，简化模拟仿真过程，提高生产率，加快产品造型和综合设计过程。标准化法标准化法是采用标准模具设计设计、标准件、和模具设计的标准工作方法。这就意味着每一个模具设计者设计模具时都将采用相同的方法，使用相同的模具装配模型树，和从精确得到产品文件中调入标准件。这就使得在模具设计工程中不同的工作组可以使用相同的语言。优点：a）容易跟进模具设计工程，b ）低成本和快速取模，c）便捷的模具工程管理器。数据库系统中使用了四个不同的数据库：a）图书数据库 时模具制造工业中常用的所以通用部件的集合，B）装配数据库是用于所有的标准件和型腔设计。所有不同的装配都已在三维实体中事先定义好了，只需把装配激活就可以。C）工程数据库是所有输入技术讨论检测表、从属设计的交换界面的数据的集合，因此对于特殊的工程增强了跟踪和交换信息的能力。不同组件的质量和类型能够被应用在工程中，同样的也能重新录入，从而当设计时很容易生成数据表(BOMs)。D）几何参数数据库应用在需要改变几何参数的地方，例如两个不同模腔之间的距离和标准件的位置等。系统实施塑料注射模具快速实现原始设计的系统模型作为电脑兼容的硬件已经被应用。这个模型系统在 Windows 环境下可以作为 CAD 软件安装在 SolidWorks 2001，作为程序语言应用在 Microsoft Visual C+ V6.0 和 SolidWorks API。这种方法，模型系统中的启发式和公式化是基于新加坡的模具制造业。总结本文主要介绍的是塑料注射器模具原始设计快速成型的标准方法。对于每一个模具设计工程，设计方法都是相同的，并在标准的模板中。当从属设计时有自己的子设计模板时，技术讨论检测表模板就成为总的标准模板。数据库的应用允许用户灵活变化。模具铸模成本在检查表中也可以自动生成。其他优点还有快速设计方法、模具设计功能和可视化。然而，这种快速成形设计有其自身的局限性。配合模具设计系统需建立技术优势、更多的数据，规则方法和启动方式，例如混合模具和薄壁模具等塑料注射9器模具新型成模方法。消费者投资机构需要投入更多的努力和财力来考虑新的技术。材料和模具机器数据库必须定时更新升级，并及时加入工业上所采用新型材料和模具机器的最新数据。假如在数据库中有一个错误的输入，那所得到的数据将是灾难性的。当设计不对时，一个有经验的设计者能够及时发现，而一个初学者会不加思考的接受，相信系统总会提供正确的解决方法。作者正在研究改进系统的方法，以便增加定制方法的实用化程度。
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