In order to establish a comprehensive functional model of a design system, usually various functional reasoning path types in the functional modeling framework should be used together to solve a complex functional design problem. For example, in a combined functional reasoning path, a desired function F5 is first realized by a physical structure S5, which may only be fully actualized due to the presence of a supportive function F51. F51 is broken down into simple sub-functions F511 and F512, followed by a further function-structure mapping and functional supportive synthesis process. As a result, a supportive function F513 is synthesized to provide support for sub-function F511, and is then realized by a physical structure S513. Sub-functions F511 and F512 are respectively realized by physical structures

S511 and S512.

In such a comprehensive functional modeling framework, it is also noted that the modeling strategy is two-way and flexible. For example, a function in the function layer can be realized by a structure in the structure layer, a transformation from the function layer to the structure layer; on the other hand, a structure in the structure layer may be fully actualized due to the presence of a supportive function in the function layer, a transformation from the structure layer to the function layer. Due to its comprehensiveness and flexibility, the proposed functional modeling framework will be used in this paper to guide conceptual die design through various functional reasoning steps including functional decomposition, functional supportive synthesis and function-structure mapping.

4. FUNCTIONAL MODELING IN CONCEPTUAL DIE

DESIGN

We consider that conceptual design is to construct a consistent and feasible functional model of a design by detailing and embodying the functional specifications on the functional modeling framework. Using a general stamping die as an illustrative example, the design specification from the functional viewpoint is an overall functional requirement, i.e.,

Perform the stamping operation. The logical steps of the conceptual die design process in a computerized design environment proceed as follows:

(1) For a desired function (or physical structure), the starting point is to consider whether it may only be actualized due to the presence of some other functions through functional supportive synthesis. If it is applicable, the latter should first be synthesized as supportive functions to generate a more complete functional design, and this point will not be repeated in the following discussion when it is not applicable. Referring to figure 3 (The legend in figure 2 is still applied here), for the overall functional requirement F1, three supportive functions F11, F12 and F13 are synthesized to fully actualize F1 in the function layer.

摘要：由于此功能的使用在决定最终产品功能起着决定性的作用，在过去的二十年间它已经被公认为设计过程中重要的一部分，特别是在概念设计阶段。尽管现在有一些综合的方法论能处理功能或功能的论证，可事实上由于商用计算机辅助设计系统集中于几何建模而不是功能建模，因此没有能证明概念设计过程的系统。这篇论文是介绍一种通过步骤分为功能的分析、功能的综合证明和功能结构计划的功能论证，类似于模具概念设计向导的功能建模。成形加工的功能模型为概念设计阶段中产生多种模具结构提供了良好的基础。因为功能是比结构更高级的抽象概念，并且促进获取设计者的意图。为获得更迅速的模具概念设计步骤，功能建模过程已经被执行于计算机化的设计环境中。

关键词：概念设计；模具结构设计；功能模型；功能建模；功能论证

1． 引言

在工程设计中，所有的产品和人造物品在生产出后都有其固有的原因：产品或人造物品的功能。换句话说，工程设计过程需要以功能为向导。概念设计阶段是设计过程中至关重要的早期阶段。初始设计的发明是为了解决设计问题的同时实现所必须的功能。功能设计对于概念设计行为的研究已经成为种新的观点，它的目的是为电脑工具提供连接功能设计和用于实现功能的结构性体现。通常设计者赞同功能是决定产品基本特性最重要的概念，因为无论细节多么精致产品，只要带有主要功能的问题就不可能被出售。