Abstract
在電腦輔助合製造的環境中, 治夾具設計的自動化系統之研發是一項重要的工作。自動化的治夾具設計系統,可以提升設計和製造部門間的整合,並且減少產品生產的前置準備時間, 增加治夾具設計的安全性和正確性。本篇論文的主要目的是發展在電腦輔助設計與製造系統中之治夾具規劃與分析。在電腦輔助治夾具規劃方面,此系統將整合模組化治夾具資料庫、治夾具夾持點決策演法及3D立體圖形模擬介面, 並根據工件的幾何資料、治夾具元件的資料和夾持點的配置資料, 進行規劃工作, 以解析出各治夾具元件在基板上的安裝位置、夾持方向及夾持高度。本系統係建構在既有的電腦輔助設計與製造系統 - CATIA 中, 夾持點決策演算法以FORTRAN程式語言撰寫,在解析出各治夾具元件的相關夾持資料後, 系統將自動的從資料庫中取出各治夾具元件的實體模形, 並按其夾持位置組裝在工件的周圍, 完成工件夾持計劃的電腦立體圖形模擬。在電腦輔助治夾具分析方面, 利用電腦輔助工程分析之有限元素分析軟體, 解析受治夾具元件夾持力和刀具切削力作用的工件, 其所受應力和彈性變形量間的線性關係。並建立一非線性最佳化模式, 以求得在施以最適切的夾持力狀況下, 工件因受力所產生的最小變形量。以此最佳化分析模式, 可用以驗證工件夾持計劃的合理性與正確性, 並可用以在數個可行的夾持計劃中, 決定最佳之工件夾持計劃。The automation of fixture design is an important issue toprompt the integration between design and manufacturing in aCIM environment. The objective of this thesis is to develop thecomputer-aided fixture design system for modular fixture setup,and the fixture analysis system for verification of fixturedesign. The computer- aided fixture design system areimplemented on a commercial CAD/CAM system, namely, CATIA. Thedetermination algorithms are derived for locating position ofmodular fixture elements on a base plate. A 3-D librarycontaining the solid models of modular fixture elements arecreated. After applying the determination algorithms, aworkpiece setup with surrounded fixture elements is displayedon the terminal. The fixture analysis system use finiteelement analysis to analyze the dynamic behavior of thefixtured workpiece. An optimization model, which is formulatedto determinate the deformation of a workpiece and theappropriate clamping forces, is constructed to find the optimalfixture design among several feasible setups. This researchfocuses on both planning and analysis in workpiece fixturing. Ascientific approach is taken to make fixture design moreefficiently and effectively than the traditional approach ofrelying on tool designer's expertise.