【正文】 )2 7 2 1 . 2 5l l lt nf?? ??? ? ??機(jī) 工序 15：檢驗(yàn) 工序 16：入庫 第 16 頁 共 32 頁 第二章 機(jī)床夾具的定位及夾緊 概述 在機(jī)械制造中，用以裝夾工件（和引導(dǎo)刀具）的裝置，稱為夾具。 （ 3）夾具體 第 17 頁 共 32 頁 夾具體是夾具的基本骨架，通過它將夾具所有的元件構(gòu)成一個(gè)整體。 （ 4） 其他元件或裝置 根據(jù)加工需要，有些夾具還分別采用分度裝置、靠模裝置、上下料裝置、 平衡塊 等 。專用夾具通常由使用廠根據(jù)要求自行設(shè)計(jì)與制造。它在使用上具有專用夾具的優(yōu)點(diǎn)，而當(dāng)產(chǎn)品更換時(shí)，不存在夾具“報(bào)廢”問 題。 機(jī)床夾具在機(jī)械加工中的作用 夾具是機(jī)械加工中的一種工藝裝備，它在生產(chǎn)中起的作用很大， 所以在機(jī)械加工中的應(yīng)用十分廣泛 。 工件的裝夾方式 工件在機(jī)床上的裝 夾 方式有以下三種方法： 1. 直接找正法 在機(jī)床上根據(jù)工件上有關(guān)基準(zhǔn)直接找正工件，使工件獲得加工的正確位置的方法。 由于夾具預(yù)先在機(jī)床上已調(diào)整好位置（也有在加工過程中再進(jìn)行找正的），因此，工件通過夾具相對(duì)于機(jī)床也就有了正確的位置 。 第 20 頁 共 32 頁 1. 設(shè)計(jì)基準(zhǔn) 在零件圖樣上所采用的基準(zhǔn)，稱為設(shè)計(jì)基準(zhǔn)。如軸心線、 對(duì)稱面等 ，它們是由某些具體表面來體現(xiàn)的。 （ 2） 不完全定位 第 21 頁 共 32 頁 根據(jù)工件的加工要求，并不需要限制工件的全部自由度，這樣的定位， 稱為不完全定位 。 1. 工件及平面定位 （ 1） 主要支承 主要支承用來限制工件的自由度，起定位作用 1）固定支承 2）可調(diào)支承 3）自位支承 （ 2） 輔助支承 提高工件的安裝剛性和穩(wěn)定性 1）螺旋式輔助支承 2）自位式輔助支承 3）推引式輔 助支承 4）液壓鎖緊的輔助支承 2. 工件以圓柱空定位 （ 1） 圓柱銷 （ 2） 圓錐銷 （ 3） 圓柱心軸 3. 工件以外圓柱面定位 （ 1）在 V 形塊中定位 （ 2）在圓孔中定位 第 22 頁 共 32 頁 （ 3）在半圓孔和圓錐孔中定位 工件的夾緊 在機(jī)械加工中，工件的定位和夾緊是相互聯(lián)系非常密切的兩個(gè)工作過程。 （ 2） 應(yīng)盡量避免或減少工件的夾緊變形 （ 3） 夾緊力作用點(diǎn)應(yīng)盡量靠近加工部位 3. 夾緊力大小的估算 （ 1） 首先假 設(shè)系統(tǒng)為剛性系統(tǒng)，切削過程處于穩(wěn)定狀態(tài)。經(jīng)指導(dǎo)老師與我協(xié)商，決定設(shè)計(jì)第 60 道工序 銑Φ 55 上端面 的專用夾具。 在此次的夾緊機(jī)構(gòu)的設(shè)計(jì)中，所采用的是 手柄螺旋 夾緊機(jī)構(gòu)。此時(shí)可求出孔心在接觸點(diǎn)與銷中心連線方向上的最大變動(dòng)量為孔徑公差多一半。 每周都會(huì)進(jìn)行疑難問題的解答，記得有一次原定于下午的答辯，由于池老師臨時(shí)有事被迫延后。s behaviors to care for eyes, basedon the timely and factual statistics the survey series of followup events will also be held in six cities, including Jinan in Shandongprovince, and Changsha in Hunan province, to educate people on how to care for eyes afterthe survey started. More and more Chinese are jogging to get and stay fit. Most joggers will run alone, but some will jog with friends or even coaches. The Beijing Olympic Forest Park is one of the most popular spots. It is packed with runners in the afternoon, usually after work, and at weekends. Jogging after a whole day39。s ovarian function has declined and a bilateral oviduct blockage has occurred, meaning that in vitro fertilization is her only option. So, after reducing her workload, Xiao underwent IVF treatment. Luckily, she got pregnant after just one treatment cycle, but later experienced vaginal bleeding, and rushed to the hospital. I told her to rest and carry on with the treatment (to prevent a miscarriage). As Zubin Zarthoshtimanesh, a yoga guru, demonstrated postures at a high school stadium in Dujiangyan city, Sichuan province, some 200 students sat on colorful mats watching him closely. It was part of the first IndiaChina international yoga festival in the provincial capital, Chengdu, in Southwest China, where more than 1,000 fans from home and abroad gathered for lessons from 20 leading practitioners of the ancient Indian regimen, from June 1721. Yoga is to India what perhaps tai chi is to China. Many countries other than India and China, also held the first World Yoga Day on June 21, after the United Nations last year agreed to Indian Prime Minister Narendra Modi39。t really matter where it originates or how it is cooked. Lin likes to give the Americanstyle restaurants39。s team of more than 550 chefs. Many of the franchise39。s Pink Revolution, an annual campaign that seeks to raise awareness and funds for breast cancer research, the hotel recently announced. A major sponsor of the campaign for three years in a row, Conrad Macao has pledged to donate a portion of its proceeds to the fund, includ ing those collected from selling its popular bear and rubber duck merchandise, in limited pink editions. Pink is the theme for floral arrangements and decorations in the hotel in October. In addition, on Fridays that month, members of the management and staff will add something pink to their uniforms, regular s and handwritten guest cards. Breast cancer is the most prevalent type of cancer among women in Hong Kong and is also of significant concern in Macao and around the world, regardless of age, general manager Bede Barry said in a statement. The hotel has enlisted the support of a number of international and local celebrities to help drive the cause, including South Korean actor Jung Suk Won. This year, a lucky guest who stays at the hotel during the campaign and also donates money for the cause will win a necklace specially designed by Arte Madrid, a Spanish jewelry brand. Women should strive to balance quality of work and life, and have children at a young age. As a doctor I see much suffering because of this imbalance. Xiao Ying, 36, works for a large law firm. Her job means lots of travel, a heavy caseload and a large number of meetings, so her schedule is hectic. She has been pregnant twice, but had abortions on both occasions because she felt her busy, highpressure career wasn39。s annual National Day for Eye Care, the China Youth Development ServiceCenter and Zhejiang Medicine, a leading listed Chinese pharmaceutical pany, jointlyannounced the kickoff of the about one month, a questionnaire piled by top eye care medical experts in China willbe distributed through multiple online partners, including , as well asthrough offline survey events held in universities, middle schools and primary schools acrossthe report will be released based on the survey statistics and analysis, and most importantly,guidelines for parents and youth on how to care for the eyes and prevent myopia — agrowing problem in China39。 每當(dāng)我遇到難以解決的問題時(shí)，我的指導(dǎo)老師池龍珠 老師 總會(huì)有問必答、知無不言 。 第 28 頁 共 32 頁 圖 3–1 夾具機(jī)構(gòu)圖 定位誤差分析與計(jì)算 工件的工序基準(zhǔn)為孔心，當(dāng)工件孔徑為最大，定位 擋 銷的孔徑為最小時(shí)，孔心在任意方向上的最大變動(dòng)量等于孔與銷配合的最大間隙量。 第 25 頁 共 32 頁 圖 31 銑 216。 典型夾緊結(jié)構(gòu) 1. 斜楔夾 緊結(jié)構(gòu) 2. 螺旋夾緊結(jié)構(gòu) （ 1） 單個(gè)螺旋夾緊結(jié)構(gòu) （ 2） 螺旋壓板夾緊結(jié)構(gòu) （ 3） 偏心夾緊機(jī)構(gòu) 定心夾緊機(jī)構(gòu) 當(dāng)加工尺寸的工序基準(zhǔn)是中心要素（軸線、中心平面等）撕，為使基準(zhǔn)重合以減少定位誤差，可以采用定位夾緊機(jī)構(gòu)，所以，定心夾緊機(jī)構(gòu)主要用于要求準(zhǔn)確定心或?qū)χ械膱?chǎng)合。只有夾緊力的作用點(diǎn)分布合理，大小適當(dāng)，方向正確才能獲得良好的效益。一種是改變定位元件的結(jié)構(gòu)，使定位元件在重復(fù)限制自由度的部分不起定位作用。通常是用一個(gè)支承點(diǎn)限制工件的一個(gè)自由度， 用合理設(shè)置的六個(gè)支承點(diǎn) ，限制工件的六個(gè)自由度，使工件在夾具中的位置完全確定，這就是