外文翻譯--注塑模具自動(dòng)裝配造型-模具設(shè)計(jì)-wenkub
2023-05-19 06:28:30 本頁(yè)面
【正文】 sses such as pocketing and interference checks. To meet these requirements, a featurebased and objectoriented hierarchical model is proposed to represent injection moulds. An assembly may be divided into subassemblies, which in turn consists of subassemblies and/or individual ponents. Thus, a hierarchical model is most appropriate for representing the structural relations between ponents. A hierarchy implies a definite assembly sequence. In addition, a hierarchical model can provide an explicit representation of the dependency of the position of one part on another. Featurebased design [10] allows designers to work at a somewhat higher level of abstraction than that possible with the direct use of solid modellers. Geometric features are instanced, sized, and located quickly by the user by specifying a minimum set of parameters, while the feature modeller works out the details. Also, it is easy to make design changes because of the associativities between geometric entities maintained in the data structure of feature modellers. Without features, designers have to be concerned with all the details of geometric construction procedures required by solid modellers, and design changes have to be strictly specified for every entity affected by the change. Moreover, the featurebased representation will provide highlevel assembly objects for designers to use. For example, while mould designers think on the level of a realworld object, . a counterbore hole, a feature object of a counterbore hole will be ready in the puter for use. Objectoriented modelling [11,12] is a new way of thinking about problems using models organised around realworld concepts. The fundamental entity is the object, which bines both data structures and behaviour in a single entity. Objectoriented models are useful for understanding problems and designing programs and databases. In addition, the objectoriented representation of assemblies makes it easy for a “child” object to inherit information from its “parent”. References [1]. K. H. Shin and K. Lee, “Design of side cores of injection moulds from automatic detection of interference faces”, Journal of Design and Manufacturing, 3(3), pp. 225–236, December 1993. [2]. Y. F. Zhang, K. S. Lee, Y. Wang, J. Y. H. Fuh and A. Y. C. Nee, “Automatic slider core creation for designing slider/lifter of injection moulds”, CIRP International Conference and Exhibition on Design and Production of Dies and Moulds, pp. 33–38, Turkey, 19–21 June 1997. [3]. E. C. Libardi, J. R. Dixon and M. K. Simmon, “Computer environments for design of mechanical assemblies: A research review”, Engineering with Computers, 3(3), pp. 121–136, 1988. [4]. K. Lee and D. C. Gossard, “A hierarchical data structure for representing assemblies”, ComputerAided Design, 17(1), pp. 15– 19, January 1985. [5]. K. Lee and D. Gossard, “Inference of position of ponents in an assembly”, ComputerAided Design, 17(1), pp. 20–24, January 1985. [6]. A. P. Ambler and R. J. Popplestone, “Inferring the positions of bodies from specified spatial relationships”, Artificial Intelligence, 6, pp. 157–174, 1975. [7]. G. Kramer, Solving Geometric Constraint Systems: A Case Study in Kinematics, MIT Press, Cambridge, MA, 1992. [8]. J. J. Shah and M. T. Rogers, “Assembly modelling as an extension of featurebased design”, Research in Engineering Design, 5(3amp。 Featurebased。 基本的圖素是能夠?qū)?shù)據(jù)庫(kù)和單一圖素的動(dòng)作聯(lián)系起來(lái)的對(duì)象。如果沒(méi)有這些特征，設(shè)計(jì)者在構(gòu)造固體模型幾何特征時(shí)就必須考慮到所有需要的細(xì)節(jié)。一級(jí)表明一個(gè)裝配順序，另外，一個(gè)分級(jí)的模型還能說(shuō)明一個(gè)部分相對(duì)于另一個(gè)部分的確定位置。 2） 成型防真應(yīng)該有象現(xiàn)實(shí)一樣的操作功能，就如 裝入和干擾檢查。在這個(gè)部分，我們基于特征和面向?qū)ο笳撌隽俗⑸淠Ｑb配。 Kruth 開(kāi)發(fā)了一個(gè)注射模的設(shè)計(jì)支援系統(tǒng)。根據(jù) Shah 和 Rogers 的分析， Kramer 的理論代表了注射模具最顯著的發(fā)展，他的特征幾何學(xué)方法能解出全部的限制條件。對(duì)于一個(gè)包括獨(dú)立元件、相互約束的標(biāo)識(shí)和不變的標(biāo)識(shí)的問(wèn)題來(lái)說(shuō)，可以用動(dòng)作分析法來(lái)解決問(wèn)題，它將一步一步地最后求出物體的最終的幾何構(gòu)造。 為了能確定出滿足一套幾何學(xué)限制條件的剛體的位置與方向， Kramer 開(kāi)發(fā)了一種 特征幾何學(xué)方法。因此，在一個(gè)完全的空間關(guān)系問(wèn)題上，有可能解出來(lái)的結(jié)果在數(shù)學(xué)理論上有效，但實(shí)際上卻是行不通的。方程式有： 16 個(gè)滿足未知條件的方程式， 18 個(gè)滿足已知條件的方程式， 6 個(gè)滿足各個(gè)矩陣的方程式以及另外的兩個(gè)滿足旋轉(zhuǎn)元件的方程式。 自動(dòng)
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