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湖南科技大學機電工程學院 機 械 加 工 工 序 卡 產(chǎn)品型號 零（部）件圖號 共 10頁 產(chǎn)品名稱 車床 零（部）件名稱 尾架體 第 1 頁 車 間 工序號 工序名稱 材料牌號 銑削車間 50 銑削 HT200 毛坯種類 毛坯外形尺寸 每毛坯件數(shù) 每臺件數(shù) 鑄件 如圖 1 1 設備名稱 設備型號 設備編號 同時加工件數(shù) 立式銑床 X53T 1 夾 具 編 號 夾 具 名 稱 切 削 液 虎口平鉗 關 工序工時 準終 單件 13.29 序號 工 步 內(nèi) 容 工 藝 裝 備 主軸 轉速 (r/min) 切削 速度 (m/min) 進給 量 (mm/min) 切削 深度 (mm) 走刀次數(shù) 時間定額 機動(min) 輔助(min) 1 粗銑表面A YG8Φ250端銑刀 71 54.95 315 4 1 1.37 0.23 2 半精銑表面A YG8Φ250端銑刀 112 86.35 110 1.5 1 3.93 0.95 3 精銑表面A YG8Φ250端銑刀 180 141.3 80 0.5 1 5.4 1.31 編制（日期） 審核（日期） 會簽（日期） 標記 處數(shù) 更改文件號 簽字 日期 標記 更改文件號 簽字 日期 湖南科技大學機電工程學院 機 械 加 工 工 序 卡 產(chǎn)品型號 零（部）件圖號 共 10頁 產(chǎn)品名稱 車床 零（部）件名稱 尾架體 第 2 頁 車 間 工序號 工序名稱 材料牌號 銑削車間 60 銑削 HT200 毛坯種類 毛坯外形尺寸 每毛坯件數(shù) 每臺件數(shù) 鑄件 如圖 1 1 設備名稱 設備型號 設備編號 同時加工件數(shù) 立式銑床 X53T 1 夾 具 編 號 夾 具 名 稱 切 削 液 虎口平鉗 關 工序工時 準終 單件 6.8 序號 工 步 內(nèi) 容 工 藝 裝 備 主軸 轉速 (r/min) 切削 速度 (m/min) 進給 量 (mm/min) 切削 深度 (mm) 走刀次數(shù) 時間定額 機動(min) 輔助(min) 1 粗銑表面B 高速鋼Φ63立銑刀 140 27.26 220 2.5 1 1.25 0.3 2 半精銑表面B 高速鋼Φ63立銑刀 180 35.04 160 1.0 1 1.72 0.38 3 精銑表面B 高速鋼Φ63立銑刀 280 55.39 110 0.5 1 2.5 0.61 編制（日期） 審核（日期） 會簽（日期） 標記 處數(shù) 更改文件號 簽字 日期 標記 更改文件號 簽字 日期 湖南科技大學機電工程學院 機 械 加 工 工 序 卡 產(chǎn)品型號 零（部）件圖號 共 10頁 產(chǎn)品名稱 車床 零（部）件名稱 尾架體 第 3 頁 車 間 工序號 工序名稱 材料牌號 切削車間 70 銑削 HT200 毛坯種類 毛坯外形尺寸 每毛坯件數(shù) 每臺件數(shù) 鑄件 如圖 1 1 設備名稱 設備型號 設備編號 同時加工件數(shù) 立式銑床 X53T 1 夾 具 編 號 夾 具 名 稱 切 削 液 虎口平鉗 關 工序工時 準終 單件 4.86 序號 工 步 內(nèi) 容 工 藝 裝 備 主軸 轉速 (r/min) 切削 速度 (m/min) 進給 量(mm/min) 切削 深度 (mm) 走刀次數(shù) 時間定額 機動(min) 輔助(min) 1 粗銑孔Φ75兩個端面 YG8Φ125端銑刀 150 58.88 300 2.5 1 1.36 0.33 2 精銑孔Φ75兩個端面 YG8Φ125端銑刀 375 147.19 150 0.5 1 2.55 0.62 編制（日期） 審核（日期） 會簽（日期） 標記 處數(shù) 更改文件號 簽字 日期 標記 更改文件號 簽字 日期 湖南科技大學機電工程學院 機 械 加 工 工 序 卡 產(chǎn)品型號 零（部）件圖號 共 10頁 產(chǎn)品名稱 車床 零（部）件名稱 尾架體 第 4 頁 車 間 工序號 工序名稱 材料牌號 切削車間 80 鏜削 HT200 毛坯種類 毛坯外形尺寸 每毛坯件數(shù) 每臺件數(shù) 鑄件 如圖 1 1 設備名稱 設備型號 設備編號 同時加工件數(shù) 臥式鏜床 T68 1 夾 具 編 號 夾 具 名 稱 切 削 液 專用鏜床夾具 關 工序工時 準終 單件 2.58 序號 工 步 內(nèi) 容 工 藝 裝 備 主軸 轉速 (r/min) 切削 速度 (m/min) 進給 量 (mm/min) 切削 深度 (mm) 走刀次數(shù) 時間定額 機動(min) 輔助(min) 1 粗鏜孔Φ75 YG6，16×16單刃鏜刀 200 45.53 1.03 2.25 1 2.08 0.5 編制（日期） 審核（日期） 會簽（日期） 標記 處數(shù) 更改文件號 簽字 日期 標記 更改文件號 簽字 日期 湖南科技大學機電工程學院 機 械 加 工 工 序 卡 產(chǎn)品型號 零（部）件圖號 共 10頁 產(chǎn)品名稱 車床 零（部）件名稱 尾架體 第 5 頁 車 間 工序號 工序名稱 材料牌號 切削車間 90 鉸削 HT200 毛坯種類 毛坯外形尺寸 每毛坯件數(shù) 每臺件數(shù) 鑄件 如圖 1 1 設備名稱 設備型號 設備編號 同時加工件數(shù) 搖臂鉆床 Z3040 1 夾 具 編 號 夾 具 名 稱 切 削 液 鉆床專用夾具 關 工序工時 準終 單件 1.74 序號 工 步 內(nèi) 容 工 藝 裝 備 主軸 轉速 (r/min) 切削 速度 (m/min) 進給 量 (mm/min) 切削 深度 (mm) 走刀次數(shù) 時間定額 機動(min) 輔助(min) 1 粗擴孔Φ36 Φ35標準高速鋼擴孔鉆 200 21.98 1.25 1 1 0.47 0.11 2 粗鉸孔Φ36 Φ35.9標準合金鋼鉸刀 200 22.55 1.25 0.45 1 0.47 0.11 3 精鉸孔Φ36 Φ36標準合金鋼鉸刀 250 28.26 1.0 0.05 1 0.47 0.11 編制（日期） 審核（日期） 會簽（日期） 標記 處數(shù) 更改文件號 簽字 日期 標記 更改文件號 簽字 日期 湖南科技大學機電工程學院 機 械 加 工 工 序 卡 產(chǎn)品型號 零（部）件圖號 共 10頁 產(chǎn)品名稱 車床 零（部）件名稱 尾架體 第 6頁 車 間 工序號 工序名稱 材料牌號 切削車間 100 鉸削 HT200 毛坯種類 毛坯外形尺寸 每毛坯件數(shù) 每臺件數(shù) 鑄件 如圖 1 1 設備名稱 設備型號 設備編號 同時加工件數(shù) 搖臂鉆床 Z3040 1 夾 具 編 號 夾 具 名 稱 切 削 液 專用鉆床夾具 關 工序工時 準終 單件 0.49 序號 工 步 內(nèi) 容 工 藝 裝 備 主軸 轉速 (r/min) 切削 速度 (m/min) 進給 量 (mm/min) 切削 深度 (mm) 走刀次數(shù) 時間定額 機動(min) 輔助(min) 1 粗擴孔Φ25 Φ24.8標準高速鋼擴孔鉆 800 24.62 0.2 4.9 1 0.17 0.04 2 粗鉸孔Φ25 Φ24.94標準合金鋼鉸刀 320 10.01 1.25 0.08 1 0.1 0.02 3 精鉸孔Φ25 Φ25標準合金鋼鉸刀 250 7.85 0.8 0.02 1 0.13 0.03 編制（日期） 審核（日期） 會簽（日期） 標記 處數(shù) 更改文件號 簽字 日期 標記 更改文件號 簽字 日期 湖南科技大學機電工程學院 機 械 加 工 工 序 卡 產(chǎn)品型號 零（部）件圖號 共 10頁 產(chǎn)品名稱 車床 零（部）件名稱 尾架體 第 7 頁 車 間 工序號 工序名稱 材料牌號 切削車間 110 鉸削 HT200 毛坯種類 毛坯外形尺寸 每毛坯件數(shù) 每臺件數(shù) HT200 如圖 1 1 設備名稱 設備型號 設備編號 同時加工件數(shù) 搖臂鉆床 Z3040 1 夾 具 編 號 夾 具 名 稱 切 削 液 專用鉆床夾具 關 工序工時 準終 單件 0.85 序號 工 步 內(nèi) 容 工 藝 裝 備 主軸 轉速 (r/min) 切削 速度 (m/min) 進給 量 (mm/min) 切削 深度 (mm) 走刀次數(shù) 時間定額 機動(min) 輔助(min) 1 粗擴孔Φ24 Φ23.8標準高速鋼擴孔鉆 320 19.90 1.0 0.9 1 0.12 0.03 2 粗鉸孔Φ24 Φ23.94標準合金鋼鉸刀 500 31.31 1.25 0.07 1 0.1 0.02 3 精鉸孔Φ24 Φ24標準合金鋼鉸刀 630 39.56 0.8 0.03 1 0.1 0.02 4 粗擴孔Φ16 Φ16標準高速鋼擴孔鉆 400 20.10 1.0 0.5 1 0.05 0.01 編制（日期） 審核（日期） 會簽（日期） 標記 處數(shù) 更改文件號 簽字 日期 標記 更改文件號 簽字 日期 湖南科技大學機電工程學院 機 械 加 工 工 序 卡 產(chǎn)品型號 零（部）件圖號 共 10頁 產(chǎn)品名稱 車床 零（部）件名稱 尾架體 第 8 頁 車 間 工序號 工序名稱 材料牌號 切削車間 120 鉸削 HT200 毛坯種類 毛坯外形尺寸 每毛坯件數(shù) 每臺件數(shù) 鑄件 如圖 1 1 設備名稱 設備型號 設備編號 同時加工件數(shù) 搖臂鉆床 Z3040 1 夾 具 編 號 夾 具 名 稱 切 削 液 專用鉆床夾具 關 工序工時 準終 單件 0.83 序號 工 步 內(nèi) 容 工 藝 裝 備 主軸 轉速 (r/min) 切削 速度 (m/min) 進給 量 (mm/min) 切削 深度 (mm) 走刀次數(shù) 時間定額 機動(min) 輔助(min) 1 粗擴孔Φ20 Φ19.8標準高速鋼擴孔鉆 320 19.90 1.0 0.9 1 0.12 0.03 2 粗鉸孔Φ20 Φ19.94標準合金鋼鉸刀 500 31.31 1.25 0.07 1 0.1 0.02 3 精鉸孔Φ20 Φ20標準合金鋼鉸刀 630 39.56 0.8 0.03 1 0.1 0.02 4 粗擴孔Φ22 Φ22標準高速鋼擴孔鉆 250 17.27 1.0 1.1 1 0.3 0.07 編制（日期） 審核（日期） 會簽（日期） 標記 處數(shù) 更改文件號 簽字 日期 標記 更改文件號 簽字 日期 湖南科技大學機電工程學院 機 械 加 工 工 序 卡 產(chǎn)品型號 零（部）件圖號 共 10頁 產(chǎn)品名稱 車床 零（部）件名稱 尾架體 第 9 頁 車 間 工序號 工序名稱 材料牌號 切削車間 130 銑削 HT200 毛坯種類 毛坯外形尺寸 每毛坯件數(shù) 每臺件數(shù) 鑄件 如圖 1 1 設備名稱 設備型號 設備編號 同時加工件數(shù) 搖臂鉆床 Z3040 1 夾 具 編 號 夾 具 名 稱 切 削 液 專用鉆床夾具 關 工序工時 準終 單件 1.84 序號 工 步 內(nèi) 容 工 藝 裝 備 主軸 轉速 (r/min) 切削 速度 (m/min) 進給 量 (mm/min) 切削 深度 (mm) 走刀次數(shù) 時間定額 機動(min) 輔助(min) 1 鉆孔4×Φ7 Φ7標準高速鋼麻花鉆 800 17.58 0.20 3.5 4 0.88 0.2 2 攻絲4×M8 M8細柄機用絲錐 400 10.05 4 0.6 0.12 編制（日期） 審核（日期） 會簽（日期） 標記 處數(shù) 更改文件號 簽字 日期 標記 更改文件號 簽字 日期 湖南科技大學機電工程學院 機 械 加 工 工 序 卡 產(chǎn)品型號 零（部）件圖號 共10頁 產(chǎn)品名稱 車床 零（部）件名稱 尾架體 第 10 頁 車 間 工序號 工序名稱 材料牌號 切削車間 140 鏜削 HT200 毛坯種類 毛坯外形尺寸 每毛坯件數(shù) 每臺件數(shù) 鑄件 如圖 1 1 設備名稱 設備型號 設備編號 同時加工件數(shù) 臥式鏜床 T68 1 夾 具 編 號 夾 具 名 稱 切 削 液 專用鏜床夾具 關 工序工時 準終 單件 18.51 序號 工 步 內(nèi) 容 工 藝 裝 備 主軸 轉速 (r/min) 切削 速度 (m/min) 進給 量 (mm/min) 切削 深度 (mm) 走刀次數(shù) 時間定額 機動(min) 輔助(min) 1 半精鏜孔Φ75 YG6，16×16單刃鏜刀 315 73.40 0.74 0.85 1 1.49 0.36 2 精鏜孔Φ75 YG6，16×16單刃鏜刀 100 23.53 0.37 0.36 1 10.81 2.62 編制（日期） 審核（日期） 會簽（日期） 標記 處數(shù) 更改文件號 簽字 日期 標記 更改文件號 簽字 日期 機 械 加 工 工 藝 過 程 卡 片 產(chǎn)品型號 零（部）件圖號 第 1 頁 產(chǎn)品名稱 車床 零（部）件名稱 尾架體 共 1 頁 材料牌號 HT200 毛坯種類 鑄件 毛坯外形尺寸 見毛坯圖 每毛坯件數(shù) 1 每臺件數(shù) 1 備注 工序號 工序名稱 工 序 內(nèi) 容 車間 工段 設備 工藝裝備 工時 準終 單件 10 鑄造 砂型鑄造，手工造型 20 冷作 清砂，去澆冒口 30 熱處理 人工時效 40 油漆 非加工表面涂防銹漆 50 銑削 銑削A表面：粗銑→半精銑→精銑 銑工 X53T YG8Φ250端銑刀 13.29 60 銑削 銑削B表面：粗銑→半精銑→精銑 銑工 X53T Φ63高速鋼立銑刀 6.8 70 銑削 銑削孔Φ75兩個端面：粗銑→精銑 銑工 X53T YG8Φ125端銑刀 4.86 80 鏜孔 粗鏜孔Φ75至72.5mm，Ra12.5μm 鏜工 T68 YG6單刃鏜刀 2.58 90 鉆鉸 粗擴孔Φ36至35mm，Ra12.5μm；粗鉸孔Φ36至35.9mm，Ra3.2； 精鉸孔Φ36至，Ra1.6 鉆工 Z3040 相應的擴孔鉆、鉸刀 1.74 100 鉆鉸 粗擴孔Φ25至24.8mm，Ra12.5μm；粗鉸孔Φ25至24.94mm，Ra3.2； 精鉸孔Φ25至，Ra1.6 鉆工 Z3040 相應的擴孔鉆、鉸刀 0.49 110 鉆鉸 粗擴孔Φ24至23.8mm，Ra12.5μm；粗鉸孔Φ24至23.94mm，Ra3.2； 精鉸孔Φ24至，Ra1.6；擴削孔Φ16 鉆工 Z3040 相應的擴孔鉆、鉸刀 0.85 120 鉆鉸 粗擴孔Φ20至19.8mm，Ra12.5μm；粗鉸孔Φ20至19.94mm，Ra3.2； 精鉸孔Φ20至，Ra1.6；擴削孔Φ22 鉆工 Z3040 相應的擴孔鉆、鉸刀 0.83 130 攻絲 鉆、攻絲4×M8 鉆工 Z3040 相應的鉆頭、絲錐 1.84 140 鏜孔 半精鏜Φ75至74.2mm；精鏜孔Φ75至 鏜工 T68 YG6單刃鏜刀、浮動鏜刀 18.51 150 檢驗 去毛刺，檢驗 160 入庫 清洗、加工表面涂除銹油、入庫 編制 （日期） 審核 （日期） 會簽 （日期） 處 數(shù) 更改文件號 簽字 日期 標記 處數(shù) 更改文件號 簽字 日期 湖 南 科 技 大 學 開題報告 學 生 姓 名： 莫一臣 學 院： 機電工程學院 專業(yè)及班級： 機設二班 學 號： 1109010108 指導教師 ： 萬林林 2015年3月18日 湖南科技大學 2015屆畢業(yè)設計（論文）開題報告 題 目 車床尾架體加工工藝與夾具設計 作者姓名 莫一臣 學號 1109010108 所學專業(yè) 機械設計制造及自動化 1、 研究的意義，同類研究工作國內(nèi)外現(xiàn)狀、存在問題（列出主要參考文獻） 意義：機械設計制造及其夾具設計是對我們完成大學四年的學習內(nèi)容后進行的總體的系統(tǒng)的復習，融會貫通四年所學的知識，將理論與實踐相結合。在畢業(yè)前進行的一次模擬訓練，為我們即將走向自己的工作崗位打下良好的基礎。[1] 國內(nèi)外現(xiàn)狀、存在問題：當今世界，工業(yè)發(fā)達國家對機床工業(yè)高度重視，競相發(fā)展機電一體化、高質量、高精、高效、自動化先進機床，以加速工業(yè)和國民經(jīng)濟的發(fā)展。隨微電子、計算機技術的進步，數(shù)控機床在20世紀80年代以后加速發(fā)展，各方用戶提出更多需求，早已成為四大國際機床展上各國機床制造商競相展示先進技術、爭奪用戶、擴大市場的焦點。美、德、日三國是當今世上在數(shù)控機床科研、設計、制造和使用上，技術最先進、經(jīng)驗最多的國家。中國加入WTO后，正式參與世界市場激烈競爭，今后如何加強機床工業(yè)實力、加速數(shù)控機床產(chǎn)業(yè)發(fā)展，實是緊迫而又艱巨的任務。[2][3] [1]關慧貞.馮辛安.機械制造裝備設計.機械工業(yè)出版社.第三版 [2]鄒青.呼詠.機械制造技術基礎課程設計指導教程.機械工業(yè)出版社.第二版 [3]高志.黃純穎.機械創(chuàng)新設計.高等教育出版社.第二版 2、 研究目標、內(nèi)容和擬解決的關鍵問題（根據(jù)任務要求進一步具體化） 本設計上車床支架零件的加工工藝規(guī)程及一些工序的專用夾具設計，車床支架零件的主要加工表面是平面及孔系。本設計遵循先面后孔的原則。并將孔與平面的加工明確劃分成粗加工和精加工階段以保證孔系加工精度。整個加工過程選用組合機床，夾具選用專用夾具，夾緊可靠，機構可以不必自鎖。因此生產(chǎn)效率較高。適用于中批量，流水線上加工，能夠滿足設計要求。 設計的重點是夾具的設計，由于工件上的孔系都要以地面作為基準加工故首先得加工出底面，為保證孔的位置和加工準確性我們一定要在加工底面的時間通過畫線找出底面的加工余量。這樣就可以更好的保證孔系的位置和加工精度。 3、 特色與創(chuàng)新之處 本課題主要是設計某機床尾架體的加工工藝及夾具的設計，在設計中采用先設計該尾架體的加工工藝在根據(jù)加工工藝來選取夾具的設計的方案和夾具的具體設計。提高結構設計能力，通過設計夾具的訓練，根據(jù)被加工零件的加工要求，設計出高效、省力，經(jīng)濟合理而能保證加工質量的夾具。 4、 擬采取的研究方法、步驟、技術路線 ① 對所給零件進行設計和建模，所給零件的工藝分析，計算、編寫各工件加工工藝； ②夾具結構的總體方案設計?； ③定位分析與夾具定位誤差的計算?； ④裝配圖的設計、零件工作圖的設計； ⑤本設計的優(yōu)缺點分析?； ⑥零件加工工藝及圖形交互式（CAD/CAM）或手工數(shù)控程序編制。 運用機械制造工藝學課程中的基本理論以及在生產(chǎn)實習中學到的實踐知識，正確地解決一個零件在加工中的定位，夾緊以及工藝路線安排，工藝尺寸確定等問題，保證零件的加工質量。使用手冊以及圖表資料，掌握與本設計有關的各種資料的名稱出處，并熟練運用。機床尾架體作為各種機床不可缺少的一部分有著它的特別作用。零件是機床尾架體，尾架安裝在機床的右端導軌上，尾架上的套筒可以安裝頂尖，以支承較長的工件的右端（即頂持工件的中心孔）、安裝鉆頭、絞刀，進行孔加工，也可以安裝絲錐攻螺紋工具、圓析牙套螺紋工具加工內(nèi)、外螺紋。尾架可以沿尾架導軌作縱向調(diào)整移動，然后壓下尾架緊固手輪將尾架夾緊在所需位置，搖動尾架手輪可以實現(xiàn)對工件的頂緊、松開或對工件進行切削的縱向進給。 5、 擬使用的主要設計、分析軟件及儀器設備 ①.計算機輔助設計軟件(CAD-Computer Aided Design) ②.Pro/Engineer操作軟件 ③.SolidWorks 6、參考文獻 [1]關慧貞.馮辛安.機械制造裝備設計.機械工業(yè)出版社. 第三版 [2]鄒青.呼詠.機械制造技術基礎課程設計指導教程.機械工業(yè)出版社.第二版 [3]高志.黃純穎.機械創(chuàng)新設計.高等教育出版社.第二版 注： 1、開題報告是本科生畢業(yè)設計（論文）的一個重要組成部分。學生應根據(jù)畢業(yè)設計（論文）任務書的要求和文獻調(diào)研結果，在開始撰寫論文之前寫出開題報告。 2、參考文獻按下列格式（A為期刊，B為專著） A：[序號]、作者（外文姓前名后，名縮寫，不加縮寫點，3人以上作者只寫前3人，后用“等”代替。）、題名、期刊名（外文可縮寫，不加縮寫點）年份、卷號（期號）：起止頁碼。 B：[序號]、作者、書名、版次、（初版不寫）、出版地、出版單位、出版時間、頁碼。 3、表中各項可加附頁。 3 湖 南 科 技 大 學 英文文獻翻譯 學 生 姓 名： 學 院： 專業(yè)及班級： 學 號： 指導教師： 年 月 日 附錄 Basic Machining Operations and Cutting Technology Machine tools have evolved from the early foot-powered lathes of the Egyptians and John Wilkinson's boring mill. They are designed to provide rigid support for both the workpiece and the cutting tool and can precisely control their relative positions and the velocity of the tool with respect to the workpiece. Basically, in metal cutting, a sharpened wedge-shaped tool removes a rather narrow strip of metal from the surface of a ductile workpiece in the form of a severely deformed chip. The chip is a waste product that is considerably shorter than the workpiece from which it came but with a corresponding increase in thickness of the uncut chip. The geometrical shape of workpiece depends on the shape of the tool and its path during the machining operation. Most machining operations produce parts of differing geometry. If a rough cylindrical workpiece revolves about a central axis and the tool penetrates beneath its surface and travels parallel to the center of rotation, a surface of revolution is produced, and the operation is called turning. If a hollow tube is machined on the inside in a similar manner, the operation is called boring. Producing an external conical surface uniformly varying diameter is called taper turning, if the tool point travels in a path of varying radius, a contoured surface like that of a bowling pin can be produced; or, if the piece is short enough and the support is sufficiently rigid, a contoured surface could be produced by feeding a shaped tool normal to the axis of rotation. Short tapered or cylindrical surfaces could also be contour formed. Flat or plane surfaces are frequently required. They can be generated by radial turning or facing, in which the tool point moves normal to the axis of rotation. In other cases, it is more convenient to hold the workpiece steady and reciprocate the tool across it in a series of straight-line cuts with a crosswise feed increment before each cutting stroke. This operation is called planning and is carried out on a shaper. For larger pieces it is easier to keep the tool stationary and draw the workpiece under it as in planning. The tool is fed at each reciprocation. Contoured surfaces can be produced by using shaped tools. Multiple-edged tools can also be used. Drilling uses a twin-edged fluted tool for holes with depths up to 5 to 10 times the drill diameter. Whether the drill turns or the workpiece rotates, relative motion between the cutting edge and the workpiece is the important factor. In milling operations a rotary cutter with a number of cutting edges engages the workpiece. Which moves slowly with respect to the cutter. Plane or contoured surfaces may be produced, depending on the geometry of the cutter and the type of feed. Horizontal or vertical axes of rotation may be used, and the feed of the workpiece may be in any of the three coordinate directions. Basic Machine Tools Machine tools are used to produce a part of a specified geometrical shape and precise I size by removing metal from a ductile material in the form of chips. The latter are a waste product and vary from long continuous ribbons of a ductile material such as steel, which are undesirable from a disposal point of view, to easily handled well-broken chips resulting from cast iron. Machine tools perform five basic metal-removal processes: I turning, planning, drilling, milling, and grinding. All other metal-removal processes are modifications of these five basic processes. For example, boring is internal turning; reaming, tapping, and counter boring modify drilled holes and are related to drilling; bobbing and gear cutting are fundamentally milling operations; hack sawing and broaching are a form of planning and honing; lapping, super finishing. Polishing and buffing are variants of grinding or abrasive removal operations. Therefore, there are only four types of basic machine tools, which use cutting tools of specific controllable geometry: 1. lathes, 2. planers, 3. drilling machines, and 4. milling machines. The grinding process forms chips, but the geometry of the abrasive grain is uncontrollable. The amount and rate of material removed by the various machining processes may be I large, as in heavy turning operations, or extremely small, as in lapping or super finishing operations where only the high spots of a surface are removed. A machine tool performs three major functions: 1. it rigidly supports the workpiece or its holder and the cutting tool; 2. it provides relative motion between the workpiece and the cutting tool; 3. it provides a range of feeds and speeds usually ranging from 4 to 32 choices in each case. Introduction of Machining Machining as a shape-producing method is the most universally used and the most important of all manufacturing processes. Machining is a shape-producing process in which a power-driven device causes material to be removed in chip form. Most machining is done with equipment that supports both the work piece and cutting tool although in some cases portable equipment is used with unsupported workpiece. Low setup cost for small Quantities. Machining has two applications in manufacturing. For casting, forging, and press working, each specific shape to be produced, even one part, nearly always has a high tooling cost. The shapes that may he produced by welding depend to a large degree on the shapes of raw material that are available. By making use of generally high cost equipment but without special tooling, it is possible, by machining; to start with nearly any form of raw material, so tong as the exterior dimensions are great enough, and produce any desired shape from any material. Therefore .machining is usually the preferred method for producing one or a few parts, even when the design of the part would logically lead to casting, forging or press working if a high quantity were to be produced. Close accuracies, good finishes. The second application for machining is based on the high accuracies and surface finishes possible. Many of the parts machined in low quantities would be produced with lower but acceptable tolerances if produced in high quantities by some other process. On the other hand, many parts are given their general shapes by some high quantity deformation process and machined only on selected surfaces where high accuracies are needed. Internal threads, for example, are seldom produced by any means other than machining and small holes in press worked parts may be machined following the press working operations. Primary Cutting Parameters The basic tool-work relationship in cutting is adequately described by means of four factors: tool geometry, cutting speed, feed, and depth of cut. The cutting tool must be made of an appropriate material; it must be strong, tough, hard, and wear resistant. The tool s geometry characterized by planes and angles, must be correct for each cutting operation. Cutting speed is the rate at which the work surface passes by the cutting edge. It may be expressed in feet per minute. For efficient machining the cutting speed must be of a magnitude appropriate to the particular work-tool combination. In general, the harder the work material, the slower the speed. Feed is the rate at which the cutting tool advances into the workpiece. "Where the workpiece or the tool rotates, feed is measured in inches per revolution. When the tool or the work reciprocates, feed is measured in inches per stroke, Generally, feed varies inversely with cutting speed for otherwise similar conditions. The depth of cut, measured inches is the distance the tool is set into the work. It is the width of the chip in turning or the thickness of the chip in a rectilinear cut. In roughing operations, the depth of cut can be larger than for finishing operations. The Effect of Changes in Cutting Parameters on Cutting Temperatures In metal cutting operations heat is generated in the primary and secondary deformation zones and these results in a complex temperature distribution throughout the tool, workpiece and chip. A typical set of isotherms is shown in figure where it can be seen that, as could be expected, there is a very large temperature gradient throughout the width of the chip as the workpiece material is sheared in primary deformation and there is a further large temperature in the chip adjacent to the face as the chip is sheared in secondary deformation. This leads to a maximum cutting temperature a short distance up the face from the cutting edge and a small distance into the chip. Since virtually all the work done in metal cutting is converted into heat, it could be expected that factors which increase the power consumed per unit volume of metal removed will increase the cutting temperature. Thus an increase in the rake angle, all other parameters remaining constant, will reduce the power per unit volume of metal removed and the cutting temperatures will reduce. When considering increase in unreformed chip thickness and cutting speed the situation is more complex. An increase in undeformed chip thickness tends to be a scale effect where the amounts of heat which pass to the workpiece, the tool and chip remain in fixed proportions and the changes in cutting temperature tend to be small. Increase in cutting speed; however, reduce the amount of heat which passes into the workpiece and this increase the temperature rise of the chip m primary deformation. Further, the secondary deformation zone tends to be smaller and this has the effect of increasing the temperatures in this zone. Other changes in cutting parameters have virtually no effect on the power consumed per unit volume of metal removed and consequently have virtually no effect on the cutting temperatures. Since it has been shown that even small changes in cutting temperature have a significant effect on tool wear rate it is appropriate to indicate how cutting temperatures can be assessed from cutting data. The most direct and accurate method for measuring temperatures in high -speed-steel cutting tools is that of Wright &. Trent which also yields detailed information on temperature distributions in high-speed-steel cutting tools. The technique is based on the metallographic examination of sectioned high-speed-steel tools which relates microstructure changes to thermal history. Trent has described measurements of cutting temperatures and temperature ?distributions for high-speed-steel tools when machining a wide range of workpiece materials. This technique has been further developed by using scanning electron ?microscopy to study fine-scale microstructure changes arising from over tempering of the tempered martens tic matrix of various high-speed-steels. This technique has also been used to study temperature distributions in both high-speed -steel single point turning tools and twist drills. Wears of Cutting Tool Discounting brittle fracture and edge chipping, which have already been dealt with, tool wear is basically of three types. Flank wear, crater wear, and notch wear. Flank wear occurs on both the major and the minor cutting edges. On the major cutting edge, which is responsible for bulk metal removal, these results in increased cutting forces and higher temperatures which if left unchecked can lead to vibration of the tool and workpiece and a condition where efficient cutting can no longer take place. On the minor cutting edge, which determines workpiece size and surface finish, flank wear can result in an oversized product which has poor surface finish. Under most practical cutting conditions, the tool will fail due to major flank wear before the minor flank wear is sufficiently large to result in the manufacture of an unacceptable component. Because of the stress distribution on the tool face, the frictional stress in the region of sliding contact between the chip and the face is at a maximum at the start of the sliding contact region and is zero at the end. Thus abrasive wear takes place in this region with more wear taking place adjacent to the seizure region than adjacent to the point at which the chip loses contact with the face. This result in localized pitting of the tool face some distance up the face which is usually referred to as catering and which normally has a section in the form of a circular arc. In many respects and for practical cutting conditions, crater wear is a less severe form of wear than flank wear and consequently flank wear is a more common tool failure criterion. However, since various authors have shown that the temperature on the face increases more rapidly with increasing cutting speed than the temperature on the flank, and since the rate of wear of any type is significantly affected by changes in temperature, crater wear usually occurs at high cutting speeds. At the end of the major flank wear land where the tool is in contact with the uncut workpiece surface it is common for the flank wear to be more pronounced than along the rest of the wear land. This is because of localised effects such as a hardened layer on the uncut surface caused by work hardening introduced by a previous cut, an oxide scale, and localised high temperatures resulting from the edge effect. This localised wear is usually referred to as notch wear and occasionally is very severe. Although the presence of the notch will not significantly affect the cutting properties of the tool, the notch is often relatively deep and if cutting were to continue there would be a good chance that the tool would fracture. If any form of progressive wear allowed to continue, dramatically and the tool would fail catastrophically, i. e. the tool would be no longer capable of cutting and, at best, the workpiece would be scrapped whilst, at worst, damage could be caused to the machine tool. For carbide cutting tools and for all types of wear, the tool is said to have reached the end of its useful life long before the onset of catastrophic failure. For high-speed-steel cutting tools, however, where the wear tends to be non-uniform it has been found that the most meaningful and reproducible results can be obtained when the wear is allowed to continue to the onset of catastrophic failure even though, of course, in practice a cutting time far less than that to failure would be used. The onset of catastrophic failure is characterized by one of several phenomena, the most common being a sudden increase in cutting force, the presence of burnished rings on the workpiece, and a significant increase in the noise level. Mechanism of Surface Finish Production There are basically five mechanisms which contribute to the production of a surface which have been machined. These are: 1．The basic geometry of the cutting process. In, for example, single point turning the tool will advance a constant distance axially per revolution of the workpiecc and the resultant surface will have on it, when viewed perpendicularly to the direction of tool feed motion, a series of cusps which will have a basic form which replicates the shape of the tool in cut. 2．The efficiency of the cutting operation. It has already been mentioned that cutting with unstable built-up-edges will produce a surface which contains hard built-up-edge fragments which will result in a degradation of the surface finish. It can also be demonstrated that cutting under adverse conditions such as apply when using large feeds small rake angles and low cutting speeds, besides producing conditions which lead to unstable built-up-edge production, the cutting process itself can become unstable and instead of continuous shear occurring in the shear zone, tearing takes place, discontinuous chips of uneven thickness are produced, and the resultant surface is poor. This situation is particularly noticeable when machining very ductile materials such as copper and aluminum. 3．The stability of the machine tool. Under some combinations of cutting conditions; workpiece size, method of clamping ,and cutting tool rigidity relative to the machine tool structure, instability can be set up in the tool which causes it to vibrate. Under some conditions this vibration will reach and maintain steady amplitude whilst under other conditions the vibration will built up and unless cutting is stopped considerable damage to both the cutting tool and workpiece may occur. This phenomenon is known as chatter and in axial turning is characterized by long pitch helical bands on the workpiece surface and short pitch undulations on the transient machined surface. 4．The effectiveness of removing swarf. In discontinuous chip production machining, such as milling or turning of brittle materials, it is expected that the chip (swarf) will leave the cutting zone either under gravity or with the assistance of a jet of cutting fluid and that they will not influence the cut surface in any way. However, when continuous chip production is evident, unless steps are taken to control the swarf it is likely that it will impinge on the cut surface and mark it. Inevitably, this marking besides looking. 5．The effective clearance angle on the cutting tool. For certain geometries of minor cutting edge relief and clearance angles it is possible to cut on the major cutting edge and burnish on the minor cutting edge. This can produce a good surface finish but, of course, it is strictly a combination of metal cutting and metal forming and is not to be recommended as a practical cutting method. However, due to cutting tool wear, these conditions occasionally arise and lead to a marked change in the surface characteristics. Limits and Tolerances Machine parts are manufactured so they are interchangeable. In other words, each part of a machine or mechanism is made to a certain size and shape so will fit into any other machine or mechanism of the same type. To make the part interchangeable, each individual part must be made to a size that will fit the mating part in the correct way. It is not only impossible, but also impractical to make many parts to an exact size. This is because machines are not perfect, and the tools become worn. A slight variation from the exact size is always allowed. The amount of this variation depends on the kind of part being manufactured. For examples part might be made 6 in. long with a variation allowed of 0.003 (three-thousandths) in. above and below this size. Therefore, the part could be 5.997 to 6.003 in. and still be the correct size. These are known as the limits. The difference between upper and lower limits is called the tolerance. A tolerance is the total permissible variation in the size of a part. The basic size is that size from which limits of size arc derived by the application of allowances and tolerances. Sometimes the limit is allowed in only one direction. This is known as unilateral tolerance.Unilateral tolerancing is a system of dimensioning where the tolerance (that is variation) is shown in only one direction from the nominal size. Unilateral tolerancing allow the changing of tolerance on a hole or shaft without seriously affecting the fit.When the tolerance is in both directions from the basic size it is known as a bilateral tolerance (plus and minus). Bilateral tolerancing is a system of dimensioning where the tolerance (that is variation) is split and is shown on either side of the nominal size. Limit dimensioning is a system of dimensioning where only the maximum and minimum dimensions arc shown. Thus, the tolerance is the difference between these two dimensions. 基本加工工序和切削技術 機床是從早期的埃及人的腳踏動力車和約翰·威爾金森的鏜床發(fā)展而來的。它們?yōu)楣ぜ偷毒咛峁﹦傂灾尾⒖梢跃_控制它們的相對位置和相對速度?；旧现v，金屬切削是指一個磨尖的鍥形工