Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/1678
標題: CAD環境下電腦輔助公差設計與分析系統
DEVELOPMENT OF A COMPUTER-AIDED TOLERANCE DESIGN AND ANALYSIS SYSTEM IN CAD ENVIRONMENT
作者: 王文瑋
Wang, Wen-Wei
關鍵字: Tolerance Design;公差設計;Solid Model;Feature;Tolerance Network;Tolerance Analysis;實體模型;特徵;公差網路;公差分析
出版社: 機械工程學系
摘要: 
摘要 目前機
械設計人員已經可以利用許多電腦輔助工具來協 助工作,然而
公差設計的工作卻多仍停留在依賴經驗值或試 誤法來完成,在效率
的考量下,以一套系統化的分析程序和 電腦輔助工具來進行公差設
計與分析已有實際的需求。本文 即針對上述的需求,在架構開放的
實體模型CAD軟體環境 下,發展一套應用軟體。
在以公差設計資料庫為主軸的架構下,本文所發展之系 統可依
其功能分成五個主要的模組以及其他次要的輔助功能 程式,這些模
組分別為(1)特徵判斷與資訊擷取模組,(2)公差 標註與資訊擷取模組
,(3)配合標註模組,(4)公差網路建構模 組,(5)公差分析介面模組
。第一個模組從B-rep實體模型中 將特徵資訊擷取出來,並且進行
特徵坐標判定與特徵凹凸判 斷,第二個模組將標註完成的公差資訊
擷取出來,並且進行 公差資訊整合,第三個模組輔助使用者將公差
配合所需的資 訊加入,第四個模組處理特徵與公差配合資訊,並建
立成有 意義的公差網路,第五個模組則將公差網路資訊轉成公差運
算系統的格式以進行公差分析。公差分析最後得到一整體產 品之誤
差範圍,讓設計者瞭解公差累積對整個產品的影響, 作為公差設計
時的參考依據。本文並且以一含C軸之CNC 車削中心主軸為例,
說明系統的使用與運作流程。

Abstract
Although mechanical designers can take the advantage of
computer-aided tools to assist their tasks, yet tolerance
design still depends on experience or trial and error
method. From the viewpoint of design efficiency,
tolerance design with systematical analysis and computer-aided
tools is an immediate requirement. This thesis is intended to
develop tolerancing software in CAD environment with an
open architecture. Based on the tolerance design
database, the system developed by this thesis contains
five main modules and several subsidiary programs. These
modules are (1) feature extraction module, (2) tolerance
specification extraction module, (3) fitting assignment
module, (4) Tolerance Network construction module, and (5)
tolerance analysis interface. The feature extraction
module extracts feature information from B-rep models. It also
determines feature coordinates and detects feature types. The
tolerance specification extraction module deals with
tolerance information, including conventional
dimensional tolerances and geometric tolerances. The
fitting assignment module assists users to assign fitting and
tolerancing attributes. The Tolerance Network construction
module constructs the Tolerance Network based on
feature, tolerancing and fitting information. The tolerance
analysis interface transforms the Tolerance Network data
to the format for an existing tolerance analysis software.
Product error resulting from tolerance analysis is shown as an
error ellipsoid. It helps designers to understand the
effects of tolerance accumulation and can be used as a
reference for tolerance design. The spindle assembly of
a CNC turning center is used as an instance to
illustrate the usage and operation flow of the developed system.
URI: http://hdl.handle.net/11455/1678
Appears in Collections:機械工程學系所

Show full item record
 

Google ScholarTM

Check


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.