形位公差理念ANSI-Y14.5.pdf

幾何尺寸及公差介紹 Geometric Dimensioning and Tolerancing (GDT) 1 題綱 Outline n 簡介 Introduction n 專門術語 Terminology n 分類＆原則 Classification and Rules n 定義＆應用 Definition and Application 簡 介 Introduction Introduction(1) 許多行業上的糾紛起源于溝通的缺乏. 在當今日益激烈的竟爭中,為讓客戶對藍圖不 發生誤解, 運用國際標準的形位公差標注是 最有效的途徑. Many of Industry’s problems stem from faulty communications. In competitive product market, it is significant to make engineering drawings that are readable - we must make drawings that cannot possibly be MISUNDERSOOD Using the GDT is an efficient way. Introduction(2) What is GDT? GDT是一個具有雙重作用的系統.首 先,它是一組用來定義被測要素形位要求 及其公差帶形狀的國際通用符號;另一方 面,它也體現了被測要素的功能要求. GDT is a dual purpose system. First it is set of standard symbols which are used to define part features and their tolerance zones. Second it is a philosophy of defining a part based on how it functions. What is GDT? • 指被測實際要素對其理想要素的變動量. The Geometric Tolerance is the amount which true elements are permitted to vary from an ideal element. Introduction(3) 公差的分類 Classification of Tolerance (1). 尺寸公差 Dimension Tolerance (2). 表面形貌公差(表面粗糙度) Surface Tolerance (Roughness) (3). 形狀和位置公差 Geometric Tolerance Introduction(4) 形位公差標準的演變歷程: 最先應用于軍事 工業, 以美國與英國應用最為廣泛,各種不同 的組織相繼出版了各種不同的標準.1966年, 第一部統一的標準 ANSI Y14.5出版,並經 歷1973,1982和1994三次改版. In 1966, the first united standard was published by the American National Standards Institute (ANSI), known as ANSI Y14.5. It was updated in 1973, 1982,1994. Introduction(5) 優點: Advantages: n 有利于增強彼此之間的交流 Improves communications n 有利于產品的設計 Better product designs n 有利于零件制造公差的盈餘 Production tolerances increased 專門術語 Terminology 1.尺寸要素 非尺寸要素 Feature-of-size and