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畢業(yè)設計說明書 第56頁
20**屆畢業(yè)設計(論文)
中間軸齒輪的加工工藝及及車床夾具設計
系 、 部:
學生姓名:
指導教師:
職 稱:
專 業(yè):
班 級:
學 號:
20**年 5 月
20** 屆畢業(yè)設計(論文)課題任務書
系: 機械工程系 專業(yè): 機械制造與自動化
指導教師
學生姓名
課題名稱
中間軸齒輪加工工藝及車床夾具設計
內容及任務
內容:
1. 名稱:中間軸齒輪
2. 材料:20Cr
3. 加工內容:
1)擴孔2)粗車外圓,粗車一端大、小端面,一端內孔倒角(3)半精車外圓,粗車另一端大、小端面,另一端內孔倒角 4)拉孔5)精車外圓,精車一端大、小端面,一端外圓倒角6)精車另一端大、小端面,另一端外圓倒角7)車槽8)中間檢驗9)滾齒10)一端齒圈倒角11)另一端齒圈倒角)12)剃齒13)檢驗14)熱處理
4. 加工精度:見被加工零件工序圖
5. 生產(chǎn)批量:5000件/年(中批)
任務:
1、編制機械加工工藝規(guī)程,填寫機械加工工藝及指定的工序卡,圖幅為A4
2、設計、繪制毛坯零件圖,圖幅為A3
3、設計、繪制指定工序的夾具裝配圖,圖幅為A1
4、 撰寫設計說明書一份。
擬達到的要求或技術指標
1、設計方案應合理可行,能達到所要求的加工精度、表面粗糙度
2、結構力求簡單、機床操作方便、使用安全可靠、制造工藝性較好
3、設計方案應能達到一定的生產(chǎn)率要求和半自動化程度
4、所有設計圖紙均符合國家規(guī)定的新標準
5、說明書內容應完整,分析要透徹,約2萬字左右。
進度安排
起止日期
工作內容
備注
20**-1-1~20**-2-1
調查研究,搜集資料
圖書館
20**-2-1~20**-2-15
擬訂開題報告,構思設計路線和方法
學校
20**-2-15~20**-2-30
設計階段第一部分,方案擬訂,繪制前期圖紙
學校
20**-2-30~20**-3-10
設計階段第二部分,齒輪設計和圖紙繪制
學校
20**-3-10~20**-3-25
擬訂中期報告
學校
20**-4-1~20**-4-25
中間軸齒輪加工工藝及車床夾具設計
學校
20**-4-25~20**-5-8
編寫畢業(yè)說明書
學校
主要參考資料
[1]《機械設計手冊》編寫組 機械設計手冊[M] 機械工業(yè)出版社會 1986
[2]龔桂義 羅圣國 機械設計課程設計指導書[M]高等教育出版社2004
[3]張展主編 機械設計通用手冊[M] 中國勞動出版社 1994、5
[4]高為國主編 機械工程材料基礎[M]中南大學出版社,2000、2
[5]周鵬翔、劉振魁主編 工程制圖[M] 高等教育出版社2000
[6]唐增寶、劉元俊主編 機械設計課程設計 華中科技大學出版社1995
教研室
意見
年 月 日
系主管領導意見
年 月 日
摘 要
本次設計內容涉及了機械制造工藝及機床夾具設計、金屬切削機床、公差配合與測量等多方面的知識。
中間軸齒輪的加工工藝規(guī)程及其車床的夾具設計是包括零件加工的工藝設計、工序設計以及專用夾具的設計三部分。在工藝設計中要首先對零件進行分析,了解零件的工藝再設計出毛坯的結構,并選擇好零件的加工基準,設計出零件的工藝路線;接著對零件各個工步的工序進行尺寸計算,關鍵是決定出各個工序的工藝裝備及切削用量;然后進行專用夾具的設計,選擇設計出夾具的各個組成部件,如定位元件、夾緊元件、引導元件、夾具體與機床的連接部件以及其它部件;計算出夾具定位時產(chǎn)生的定位誤差,分析夾具結構的合理性與不足之處,并在以后設計中注意改進。
關鍵詞:工藝;工序;切削用量;夾緊;定位;誤差
Abstract
This design content has involved the machine manufacture craft and the engine bed jig design, the metal-cutting machine tool, the common difference coordination and the survey and so on the various knowledge.
The reduction gear box body components technological process and its the processing hole jig design is includes the components processing the technological design, the working procedure design as well as the unit clamp design three parts. Must first carry on the analysis in the technological design to the components, understood the components the craft redesigns the semi finished materials the structure, and chooses the good components the processing datum, designs the components the craft route; After that is carrying on the size computation to a components each labor step of working procedure, the key is decides each working procedure the craft equipment and the cutting specifications; Then carries on the unit clamp the design, the choice designs the jig each composition part, like locates the part, clamps the part, guides the part, to clamp concrete and the engine bed connection part as well as other parts; Position error which calculates the jig locates when produces, analyzes the jig structure the rationality and the deficiency, and will design in later pays attention to the improvement.
Keywords: The craft; the working procedure; the cutting specifications; clamp; the localization; the error
目 錄
1.設計任務………………………………………………………………………4
2.零件圖分析……………………………………………………………………5
2.1、零件的功用……………………………………………………………5
2.2、零件功用分析…………………………………………………………5
3.確定毛坯………………………………………………………………………6
3.1、確定毛坯制造方法……………………………………………………6
3.2、確定總余量……………………………………………………………6
3.3、繪制毛坯圖……………………………………………………………7
4.制定零件工藝規(guī)程……………………………………………………………8
4.1、選擇表面加工方法……………………………………………………8
4.2、選擇定位基準…………………………………………………………12
4.3、擬定零件加工工藝路線………………………………………………12
4.4、選擇各工序所用機床、夾具、刀具、量具和輔具…………………13
4.5、填寫工藝過程卡片……………………………………………………16
4.6、機械加工工序設計……………………………………………………17
4.7、機械加工工序設計(續(xù))……………………………………………21
5.夾具設計………………………………………………………………………30
5.1、功能分析與夾具總體結構設計………………………………………30
5.2、夾具設計計算…………………………………………………………30
5.3、夾具制造與操作說明…………………………………………………32
6.小結……………………………………………………………………………33
參考文獻…………………………………………………………………………34
致謝………………………………………………………………………………35
1、 設計任務
設計"中間軸齒輪"零件(圖1)機械加工工藝規(guī)程及某一重要工序的夾具。年產(chǎn)5000件
圖S0-1 中間軸齒輪
2.零件圖分析
2.1、零件的功用
本零件為拖拉機變速箱中倒速中間軸齒輪,其功用是傳遞動力和改變輸出軸運動方向。
2.2、零件工藝分析
本零件為回轉體零件,其最主要加工面是φ62H7孔和齒面,且兩者有較高的同軸度要求,是加工工藝需要重點考慮的問題。其次兩輪轂端面由于裝配要求,對φ62H7孔有端面跳動要求。最后,兩齒圈端面在滾齒時要作為定位基準使用,故對φ62H7孔也有端面跳動要求。這些在安排加工工藝時也需給予注意。
3 確定毛坯
3.1、確定毛坯制造方法
本零件的主要功用是傳遞動力,其工作時需承受較大的沖擊載荷,要求有較高的強度和韌性,故毛坯應選擇鍛件,以使金屬纖維盡量不被切斷。又由于年產(chǎn)量為5000件,達到了批量生產(chǎn)的水平,且零件形狀較簡單,尺寸也不大,故應采用模鍛。
3.2、確定總余量
由表S-1確定直徑上總余量為6mm,高度(軸向)方向上總余量為5mm。
3.3、繪制毛坯圖(圖2)
圖2 中間軸齒輪毛坯圖
4、制定零件工藝規(guī)程
4.1、選擇表面加工方法
1) φ62H7孔 參考表S-7
考慮:① 生產(chǎn)批量較大,應采用高效加工方法;② 零件熱處理會引起較大變形,為保證φ62H7孔的精度及齒面對φ62H7孔的同軸度,熱處理后需對該孔再進加
工。故確定熱前采用擴孔-拉孔的加工方法,熱后采用磨孔方法。
2) 齒面 根據(jù)精度8-7-7的要求,并考慮生產(chǎn)批量較大,故采用滾齒-剃齒的加工方法(表S-3)。
3)大小端面 采用粗車-半精車-精車加工方法(參考表S-4)。
4) 環(huán)槽 采用車削方法。
4.2、選擇定位基準
1)精基準選擇 齒輪的設計基準是φ62H7孔,根據(jù)基準重合原則,并同時考慮統(tǒng)一精基準原則,選φ62H7孔作為主要定位精基準。考慮定位穩(wěn)定可靠,選一大端面作為第二定位精基準。
在磨孔工序中,為保證齒面與孔的同軸度,選齒面作為定位基準。
在加工 環(huán)槽工序中,為裝夾方便,選外圓表面作為定位基準。
2) 粗基準選擇 重要考慮裝夾方便、可靠,選一大端面和外圓作為定位粗基準。
4.3、擬定零件加工工藝路線
方案1:
1)擴孔(立式鉆床,氣動三爪卡盤);
2)粗車外圓,粗車一端大、小端面,一端內孔倒角(多刀半自動車床,氣動可脹心軸);
3)半精車外圓,粗車另一端大、小端面,另一端內孔倒角(多刀半自動車床,氣動可脹心軸);
4)拉孔(臥式拉床,拉孔夾具);
5)精車外圓,精車一端大、小端面,一端外圓倒角(普通車床,氣動可脹心軸);
6)精車另一端大、小端面,另一端外圓倒角(普通車床,氣動可脹心軸);
7)車槽(普通車床,氣動三爪卡盤);
8)中間檢驗;
9)滾齒(滾齒機,滾齒夾具);
10)一端齒圈倒角(倒角機,倒角夾具);
11)另一端齒圈倒角(倒角機,倒角夾具);
12)剃齒(剃齒機,剃齒心軸);
13)檢驗;
14)熱處理;
15)磨孔(內圓磨床,節(jié)圓卡盤);
16)最終檢驗。
方案2:
1)粗車一端大、小端面,粗車、半精車內孔,一端內孔倒角(普通車床,三爪卡盤);
2)粗車、半精車外圓,粗車另一端大、小端面,另一端外圓、內孔倒角(普通車床,三爪卡盤);
3)精車內孔,車槽,精車另一端大、小端面,另一端外圓倒角(普通車床,三爪卡盤);
4)精車外圓,精車一端大、小端面(普通車床,可脹心軸);
5)中間檢驗;
6)滾齒(滾齒機,滾齒夾具);
7)一端齒圈倒角(倒角機,倒角夾具);
8)另一端齒圈倒角(倒角機,倒角夾具);
9)剃齒(剃齒機,剃齒心軸);
10)檢驗;
11)熱處理;
12)磨孔(內圓磨床,節(jié)圓卡盤);
13)最終檢驗。
方案比較:
方案2工序相對集中,便于管理,且由于采用普通機床,較少使用專用夾具,易于實現(xiàn)。方案1則采用工序分散原則,各工序工作相對簡單??紤]到該零件生產(chǎn)批量較大,工序分散可簡化調整工作,易于保證加工質量,且采用氣動夾具,可提高加工效率,故采用方案1較好。
4.4 選擇各工序所用機床、夾具、刀具、量具和輔具(表S-5,表S-6)
4.5 填寫工藝過程卡片
工藝過程卡片
4.6、機械加工工序設計
工序02
1)刀具安裝 由于采用多刀半自動車床,可在縱向刀架上安裝一把左偏刀(用于車削外圓)和一把45°彎頭刀(用于車倒角);可在橫刀架上安裝兩把45°彎頭刀(用于車削大、小端面)。加工時兩刀架同時運動,以減少加工時間(圖S0-3)。
圖S0-3 工序02排刀圖
2) 走刀長度與走刀次數(shù) 以外圓車削為例,若采用75°偏刀,則由表15-1可確定走刀長度為25+1+2=28mm;一次走刀可以完成切削(考慮到模角及飛邊的影響,最大切深為3-4mm)。
3) 切削用量選擇
① 首先確定背吃刀量:考慮到毛坯為模鍛件,尺寸一致性較好,且留出半精車和精車余量后(直徑留3 mm),加工余量不是很大,一次切削可以完成。?。?
aP =(140-133)/2 - 12.5×tan(7°)= 3mm;考慮毛坯誤差,?。篴P = 4 mm;
② 確定進給量:參考表S-7,有:f = 0.6 mm/ r;
③ 最后確定切削速度:參考表S-8,有:v = 1.5m/s,n = 212r/min。
4)工時計算
① 計算基本時間:tm = 28 /(212×0.6)= 0.22min(參考式S-3);
② 考慮多刀半自動車床加工特點(多刀加工,基本時間較短,每次更換刀具后均需進行調整,即調整時間所占比重較大等),不能簡單用基本時間乘系數(shù)的方法確定工時。可根據(jù)實際情況加以確定:TS = 2.5min。
該工序的工序卡片見表。
機械制造與自動化
機械加工工藝卡片
工序名稱
粗 車
工序號
02
零件名稱
中間軸齒輪
零件圖號
45-1082
零件重量
同時加工零件數(shù)
1
材料
毛坯
牌號
硬度
型式
重量
20Cr
HRc58-64
模鍛件
設備
夾具
輔助工具
名稱
型號
氣動可脹心軸
縱向刀架
橫向刀架
多刀半自動車床
C7620
工序號
工 步 內 容
刀 具
量具
走
刀
長
度
m m
走刀
次數(shù)
背吃刀量 mm
進給
量
mm/r
主軸
轉數(shù)r/mm
切削
速度
m/s
工時min
1
2
粗車外圓,保證尺寸φ140
倒角3
粗車大、小,保證23.50.3和尺寸100.2
左偏刀彎頭刀
彎頭刀
游標卡尺
0-200
游標卡尺
0-200
30
25
1
1
3
2
0.6
0.6
212
212
1.5
1.5
設計者
楊洪源
指導老師
隆文革
共 4 頁
第1 頁
4.7、機械加工工序設計(續(xù))
工序06
1)刀具安裝 由于在普通車床上加工,盡量減少刀具更換次數(shù),可采用一把45°彎頭刀(用于車削大、小端面)和一把75°左偏刀(用于倒角),見圖S0-4。
圖S0-4 工序06刀具安裝示意圖
2)走刀長度與走刀次數(shù) 考慮大端面,采用45°彎頭刀,由表S-9可確定走刀長度為27.5+1+1≈30mm;因為是精車,加工余量只有0.5 mm,一次走刀可以完成切削。小端面和倒角也一次走刀完成。
3)切削用量選擇
① 首先確定背吃刀量:精車余量0.5mm,一次切削可以完成。取:aP = 0.5mm;
② 確定進給量:參考表S-10,有:f = 0.2 mm/ r;
③ 最后確定切削速度:參考表S-8,有:v = 1.8m/s,n = 264r/min。
4)工時計算
① 計算基本時間:tm =(30 +8 + 3)/(264×0.2)≈ 0.8 min(參考式S-3);
② 考慮到該工序基本時間較短,在采用基本時間乘系數(shù)的方法確定工時,系數(shù)應取較大值(或輔助時間單獨計算)。可得到:TS = 2×tm = 1.6 min。
湖南工學院
機械制造與自動化
機械加工工藝卡片
工序名稱
精 車
工序號
05
零件名稱
中間軸齒輪
零件圖號
45-1082
零件重量
同時加工零件數(shù)
1
材料
毛坯
牌號
硬度
型式
重量
20Cr
HRc58-64
模鍛件
設備
夾具
輔助工具
名稱
型號
氣動可脹心軸
工序09
1) 工件安裝 由于滾齒加工時切入和切出行程較大,為減少切入、切出行程時間,采用2件一起加工的方法(見圖)。
圖 工序09工件安裝示意圖
2) 走刀長度與走刀次數(shù) 滾刀直徑為120mm,則由圖S0-5可確定走刀長度為:
走刀次數(shù):1
3)切削用量選擇
① 確定進給量:參考表S-11,有:
f = 1.2 mm/工件每轉;
② 確定切削速度:參考表S-12,有:v = 0.6m/s,計算求出n = 96r/min;
③ 確定工件轉速:滾刀頭數(shù)為1,工件齒數(shù)為25,工件轉速為:nw = 96/25≈4 r/min。
4)工時計算
① 計算基本時間:tm =140 / [(4×1.2)×2 ] ≈ 14 min(參考式S-3);
② 考慮到該工序基本時間較長,在采用基本時間乘系數(shù)的方法確定工時,系數(shù)應取較小值(或輔助時間單獨計算)。可得到:TS = 1.4×tm ≈ 20 min。
該工序的工序卡片見表。
湖南工學院
機械制造與自動化
機械加工工藝卡片
工序名稱
滾 齒
工序號
09
零件名稱
中間軸齒輪
零件圖號
45-1082
零件重量
同時加工零件數(shù)
2
材料
毛坯
牌號
硬度
型式
重量
20Cr
HRc58-64
模鍛件
設備
夾具
輔助工具
名稱
型號
滾齒夾具
滾齒機
Y3150
工序號
工 步 內 容
刀 具
量具
走
刀
長
度
m m
走刀
次數(shù)
背吃刀量 mm
進給
量
mm/r
主軸
轉數(shù)r/mm
切削
速度
m/s
工時min
1
滾齒,保證公法線平均長度;公法線長度變動量不大于0.036,在齒輪綜合檢查儀上測量,齒圈跳動量不大于0.06
剃齒滾刀
游標卡尺
25-50
百分表0-10
檢驗心軸
標準齒輪
綜合檢查儀
136
1
12.5
96
20
設計者
楊洪源
指導老師
隆文革
共 4 頁
第 3頁
工序13
1) 走刀長度與走刀次數(shù) 走刀長度?。篖=l=40mm;走刀次數(shù):0.2/0.01=20(雙行程)。
2)切削用量選擇(參考表S-13)
① 確定砂輪速度:取砂輪直徑d =50 mm,砂輪轉速n = 10000r/min,可求出砂輪線速度:
v = 26m/s;
② 確定工件速度:取vw = 0.12 m/s;可計算出工件轉數(shù)nw = 36 r/min;
③ 確定縱向進給量:取fl = 3m/min;
④ 確定橫向進給量:取fr= 0.01mm/雙行程;
⑤ 確定光磨次數(shù):4次/雙行程。
3)工時計算
① 計算基本時間:tm =(40×2/(3×1000))×(20+4)×K
K是加工精度系數(shù),取K=2,得到:tm = 1.28 min;
② 考慮到該工序基本時間較短,在采用基本時間乘系數(shù)的方法確定工時,系數(shù)應取較大值(或輔助時間單獨計算)。可得到:TS = 2.4×tm = 3 min。
該工序的工序卡片見表。
湖南工學院
機械制造與自動化
機械加工工藝卡片
工序名稱
磨孔
工序號
15
零件名稱
中間軸齒輪
零件圖號
45-1082
零件重量
同時加工零件數(shù)
1
材料
毛坯
牌號
硬度
型式
重量
20Cr
HRc58-64
模鍛件
設備
夾具
輔助工具
名稱
型號
節(jié)圓卡盤
內圓磨床
M2120
工序號
工 步 內 容
刀 具
量具
走
刀
長
度
m m
走刀
次數(shù)
背吃刀量 mm
進給
量
mm/r
主軸
轉數(shù)r/mm
切削
速度
m/s
工時min
1
磨孔,保證孔徑φ及對齒圈的同軸(在齒輪綜合檢查儀上測量,齒圈跳動量不大于0.06)
砂輪
塞規(guī)φ62H百分表0-10
檢驗心軸
標準齒輪
綜合檢查儀
40
24
0.01
3
10000
26
3
設計者
楊洪源
指導老師
隆文革
共 4 頁
第 4頁
5.夾具設計
5.1、功能分析與夾具總體結構設計
本工序要求以φ61.6H8孔(4點)和已加工好的大端面(1點)定位,精車另一大、小端面及外圓倒角(5×15°),并要求保證尺寸20±0.2和10±0.2以及大、小端面對φ61.6H8孔的跳動不大于0.05mm。其中端面跳動是加工的重點和難點,也是夾具設計需要著重考慮的問題。
夾具方案設計
工件以孔為主要定位基準,多采用心軸。而要實現(xiàn)孔4點定位和端面1點定位,應采用徑向夾緊??捎幸韵聨追N不同的方案:
1) 采用脹塊式自動定心心軸;
2) 采用過盈配合心軸;
3) 采用小錐度心軸;
4) 采用彈簧套可脹式心軸;
5) 采用液塑心軸。
根據(jù)經(jīng)驗,方案1定位精度不高,難以滿足工序要求。方案2和3雖可滿足工序要求,但工件裝夾不方便,影響加工效率。方案4可行,即可滿足工序要求,裝夾又很方便。方案5可滿足工序要求,但夾具制造較困難。故決定采用方案4。
夾具總體結構設計
1) 根據(jù)車間條件(有壓縮空氣管路),為減小裝夾時間和減輕裝夾勞動強度,宜采用氣動夾緊。
2) 夾具體與機床主軸采用過渡法蘭連接,以便于夾具制造與夾具安裝。
3) 為便于制造,彈簧套采用分離形式。
5.2、夾具設計計算
切削力計算(參考切削用量手冊)
主切削力:
進給抗力(軸向切削力):
最大扭矩:
夾緊力計算(參考夾具設計手冊)
式中φ1 -- 彈簧套與夾具體錐面間的摩擦角,?。簍anφ1=0.15;
φ2 -- 彈簧套與工件間的摩擦角,取:tanφ2=0.2;
α-- 彈簧套半錐角,α=6°;
D -- 工件孔徑;
Fd -- 彈性變形力,按下式計算:
式中C -- 彈性變形系數(shù),當彈簧套瓣數(shù)為3、4、6時,其值分別為300、100、20;
d -- 彈簧套外徑;
l -- 彈簧套變形部分長度;
t -- 彈簧套彎曲部分平均厚度;
Δ-- 彈簧套(未脹開時)與工件孔之間的間隙。
將有關參數(shù)代入,得到:
將Fd 及其他參數(shù)代入,得到:
選擇氣缸形式,確定氣缸規(guī)格(參考夾具設計手冊)
選擇單活塞回轉式氣缸,缸徑100mm即可。
5.3、夾具制造與操作說明
夾具制造的關鍵是夾具體與彈簧套。夾具體要求與彈簧套配合的錐面與安裝面有嚴格的位置關系,彈簧套則要求與夾具體配合的錐面與其外圓表面嚴格同軸。此外,彈簧套錐面與夾具體錐面應配做,保證接觸面大而均勻。
夾具使用時必須先安裝工件,再進行夾緊,嚴格禁止在不安裝工件的情況下操作氣缸,以防止彈簧套的損壞。
夾具裝配圖見圖。
6 小結
通過這為期半個學期的畢業(yè)設計,我收獲良多。
首先,我所設計的零件很復雜而且形狀也不規(guī)則,這使本就很大的工作量變得更大了,以致于我每天都要看書,查閱大量的資料,毫不懈怠,希望能按時完成畢業(yè)設計的任務。不過,任何事物都具有兩面性,雖然我們工作很累很辛苦,但是我們從中學到了很多東西,查漏補缺,也彌補了過去所學知識的缺陷和不足,更加完善了自己,提高了自己。
由于畢業(yè)設計的涉及面廣,牽扯到的知識很多,在設計的過程中必然要翻閱很多的資料和工具書,這就需要我們到圖書館去借閱資料,再一次鍛煉了我們查閱資料和自覺學習的能力。更重要的是,在設計的過程中綜合運用了以前所學的相關知識,這是一次很好的復習機會。通過對知識的綜合運用,融會貫通,鞏固和加深了知識,也達到了溫故知新的目的。同時,這次設計也給了我一個實踐的機會。以前我們所學得知識都來源于書本上的條條框框,學得是前人的經(jīng)驗,不是自己切身體會的東西,枯燥無味?,F(xiàn)在運用到實踐中去,指導實踐,學以致用,覺得很有意義,也使我對學習和探索新知識、新領域產(chǎn)生了濃厚的興趣。
總之,這次設計我收益匪淺,很好地得到一次鍛煉。作為我人生中的一次重要經(jīng)歷,我會永遠銘記于心。
參考文獻
[1]《機械設計手冊》編寫組 機械設計手冊[M] 機械工業(yè)出版社會 1986
[2]龔桂義 羅圣國 機械設計課程設計指導書[M]高等教育出版社2004
[3]張展主編 機械設計通用手冊[M] 中國勞動出版社 1994、5
[4]高為國主編 機械工程材料基礎[M]中南大學出版社,2000、2
[5]周鵬翔、劉振魁主編 工程制圖[M] 高等教育出版社2000
[6]唐增寶、劉元俊主編 機械設計課程設計 華中科技大學出版社1995
致 謝
經(jīng)過兩個月的刻苦攻關,終于就要完成大學三年中最重要的畢業(yè)設計。這對我來說,不僅是一次挑戰(zhàn)、一次嘗試,更是一次絕好的鍛煉,能夠為我以后參加工作增加必不可少的經(jīng)驗。
在整個畢業(yè)設計的過程當中,肯定不會是一帆風順的,我經(jīng)常在面對這些難題的時候一籌莫展。幸虧有**教授的指導和同學們的支持,我才能將難題一一解開,順利的完成這次畢業(yè)設計。所以,在此要特別感謝**教授對我的支持和幫助以及同學們給予我的鼓勵。
另外,我還要特別感謝同學們對我實踐以及論文寫作的指導,他們?yōu)槲彝瓿蛇@篇論文也提供了巨大的幫助。
最后,再次對關心、幫助我的老師和同學表示衷心地感謝。
56
過程卡片
工
序
號
工序名稱及內容
機 床
夾具
刀 具
量 具
輔具
工時
名稱
規(guī)格
名稱
規(guī)格
名稱
規(guī)格
01
擴空
立式鉆床
Z550
氣動三
爪卡盤
擴孔鉆
Φ60.5
塞 規(guī)
Φ60.5
02
粗車外圓,粗車一端大、小端面,一端內孔倒角
多刀半自動車床
C7125
氣動可
脹心軸
左偏刀
彎頭刀
90o
45o
游標卡尺
0.05/
200
03
半精車外圓,粗車,另一大、小端面,另一端內孔倒角
多刀半自動車床
C7125
氣動可
脹心軸
左偏刀
彎頭刀
90o
45o
游標卡尺
φ61.6
04
拉孔
臥式拉床
L6120
拉孔夾
具
拉刀
塞規(guī)
0.05/2000-5
05
精車外圓,精車一端大、小端面,一端外圓倒角
普通車床
C6132
氣動可
脹心軸
彎頭刀
45o
游標卡尺
百分表
檢驗心軸
φ61.6
0.05/2000-5
頂尖座
06
精車另一端大、小端面,另一端外圓倒角
普通車床
C6132
氣動可
脹心軸
右偏刀
彎頭刀
75o
45o
游標卡尺
百分表
檢驗心軸
0.05/2000-5
頂尖座
07
車槽
普通車床
C6132
三爪卡盤
切槽鏜刀
內槽卡板
08
中間檢驗
塞規(guī)
游標卡尺
檢驗心軸內槽卡板
0.05/2000-5
頂尖座
09
滾齒
滾齒機
Y3150
滾齒夾具
剃前滾刀
公法線千分尺
25-50
滾刀桿
10
一齒圈端倒角
倒角機
Y9332
倒角夾具
倒角刀
定位裝置
11
另一齒圈端倒角
倒角機
Y9332
倒角夾具
倒角刀
定位裝置
12
剃齒
剃齒機
Y4232
剃齒心軸
剃齒刀
公法線千分尺 標準齒輪 綜合檢查儀
25-50
13
檢驗
公法線千分 尺 標準齒輪 綜合檢查儀
25-50
14
熱處理
15
磨孔
內圓磨床
M2120
節(jié)圓卡盤
砂輪
塞規(guī)
φ62H
16
最終檢驗
公法線千分尺 標準齒輪 綜合檢查儀
Φ62H
25-50
頂尖座
設計者
指導老師
共 1 頁
共 1頁
附件圖紙
零件圖
V型塊
氣動可脹心軸
夾具裝配圖
外文原文:
GEAR AND SHAFT INTRODUCTION
Abstract: The important position of the wheel gear and shaft can't falter in traditional machine and modern machines. The wheel gear and shafts mainly install the direction that delivers the dint at the principal axis box. The passing to process to make them can is divided into many model numbers, useding for many situations respectively. So we must be the multilayers to the understanding of the wheel gear and shaft in many ways .
Key words: Wheel gear; Shaft
In the force analysis of spur gears, the forces are assumed to act in a single plane. We shall study gears in which the forces have three dimensions. The reason for this, in the case of helical gears, is that the teeth are not parallel to the axis of rotation. And in the case of bevel gears, the rotational axes are not parallel to each other. There are also other reasons, as we shall learn.
Helical gears are used to transmit motion between parallel shafts. The helix angle is the same on each gear, but one gear must have a right-hand helix and the other a left-hand helix. The shape of the tooth is an involute helicoid. If a piece of paper cut in the shape of a parallelogram is wrapped around a cylinder, the angular edge of the paper becomes a helix. If we unwind this paper, each point on the angular edge generates an involute curve. The surface obtained when every point on the edge generates an involute is called an involute helicoid.
The initial contact of spur-gear teeth is a line extending all the way across the face of the tooth. The initial contact of helical gear teeth is a point, which changes into a line as the teeth come into more engagement. In spur gears the line of contact is parallel to the axis of the rotation; in helical gears, the line is diagonal across the face of the tooth. It is this gradual of the teeth and the smooth transfer of load from one tooth to another, which give helical gears the ability to transmit heavy loads at high speeds. Helical gears subject the shaft bearings to both radial and thrust loads. When the thrust loads become high or are objectionable for other reasons, it may be desirable to use double helical gears. A double helical gear (herringbone) is equivalent to two helical gears of opposite hand, mounted side by side on the same shaft. They develop opposite thrust reactions and thus cancel out the thrust load. When two or more single helical gears are mounted on the same shaft, the hand of the gears should be selected so as to produce the minimum thrust load.
Crossed-helical, or spiral, gears are those in which the shaft centerlines are neither parallel nor intersecting. The teeth of crossed-helical fears have point contact with each other, which changes to line contact as the gears wear in. For this reason they will carry out very small loads and are mainly for instrumental applications, and are definitely not recommended for use in the transmission of power. There is on difference between a crossed heli
cal gear and a helical gear until they are mounted in mesh with each other. They are manufactured in the same way. A pair of meshed crossed helical gears usually have the same hand; that is ,a right-hand driver goes with a right-hand driven. In the design of crossed-helical gears, the minimum sliding velocity is obtained when the helix angle are equal. However, when the helix angle are not equal, the gear with the larger helix angle should be used as the driver if both gears have the same hand.
Worm gears are similar to crossed helical gears. The pinion or worm has a small number of teeth, usually one to four, and since they completely wrap around the pitch cylinder they are called threads. Its mating gear is called a worm gear, which is not a true helical gear. A worm and worm gear are used to provide a high angular-velocity reduction between nonintersecting shafts which are usually at right angle. The worm gear is not a helical gear because its face is made concave to fit the curvature of the worm in order to provide line contact instead of point contact. However, a disadvantage of worm gearing is the high sliding velocities across the teeth, the same as with crossed helical gears.
Worm gearing are either single or double enveloping. A single-enveloping gearing is one in which the gear wraps around or partially encloses the worm.. A gearing in which each element partially encloses the other is, of course, a double-enveloping worm gearing. The important difference between the two is that area contact exists between the teeth of double-enveloping gears while only line contact between those of single-enveloping gears. The worm and worm gear of a set have the same hand of helix as for crossed helical gears, but the helix angles are usually quite different. The helix angle on the worm is generally quite large, and that on the gear very small. Because of this, it is usual to specify the lead angle on the worm, which is the complement of the worm helix angle, and the helix angle on the gear; the two angles are equal for a 90-deg. Shaft angle.
When gears are to be used to transmit motion between intersecting shaft, some of bevel gear is required. Although bevel gear are usually made for a shaft angle of 90 deg. They may be produced for almost any shaft angle. The teeth may be cast, milled, or generated. Only the generated teeth may be classed as accurate. In a typical bevel gear mounting, one of the gear is often mounted outboard of the bearing. This means that shaft deflection can be more pronounced and have a greater effect on the contact of teeth. Another difficulty, which occurs in predicting the stress in bevel-gear teeth, is the fact the teeth are tapered.
Straight bevel gears are easy to design and simple to manufacture and give very good results in service if they are mounted accurately and positively. As in the case of squr gears, however, they become noisy at higher values of the pitch-line velocity. In these cases it is often go
www.mapeng.net 馬棚網(wǎng)
od design practice to go to the spiral bevel gear, which is the bevel counterpart of the helical gear. As in the case of helical gears, spiral bevel gears give a much smoother tooth action than straight bevel gears, and hence are useful where high speed are encountered.
It is frequently desirable, as in the case of automotive differential applications, to have gearing similar to bevel gears but with the shaft offset. Such gears are called hypoid gears because their pitch surfaces are hyperboloids of revolution. The tooth action between such gears is a combination of rolling and sliding along a straight line and has much in common with that of worm gears.
A shaft is a rotating or stationary member, usually of circular cross section, having mounted upon it such elementsas gears, pulleys, flywheels, cranks, sprockets, and other power-transmission elements. Shaft may be subjected to bending, tension, compression, or torsional loads, acting singly or in combination with one another. When they are combined, one may expect to find both static and fatigue strength to be important design considerations, since a single shaft may be subjected to static stresses, completely reversed, and repeated stresses, all acting at the same time.
The word “shaft” covers numerous variations, such as axles and spindles. Anaxle is a shaft, wither stationary or rotating, nor subjected to torsion load. A shirt rotating shaft is often called a spindle.
When either the lateral or the torsional deflection of a shaft must be held to close limits, the shaft must be sized on the basis of deflection before analyzing the stresses. The reason for this is that, if the shaft is made stiff enough so that the deflection is not too large, it is probable that the resulting stresses will be safe. But by no means should the designer assume that they are safe; it is almost always necessary to calculate them so that he knows they are within acceptable limits. Whenever possible, the power-transmission elements, such as gears or pullets, should be located close to the supporting bearings, This reduces the bending moment, and hence the deflection and bending stress.
Although the von Mises-Hencky-Goodman method is difficult to use in design of shaft, it probably comes closest to predicting actual failure. Thus it is a good way of checking a shaft that has already been designed or of discovering why a particular shaft has failed in service. Furthermore, there are a considerable number of shaft-design problems in which the dimension are pretty well limited by other considerations, such as rigidity, and it is only necessary for the designer to discover something about the fillet sizes, heat-treatment, and surface finish and whether or not shot peening is necessary in order to achieve the required life and reliability.
Because of the similarity of their functions, clutches and brakes are treated together. In a simplified dynamic representation of a friction clutch, or brake, two in
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ertias I1 and I2 traveling at the respective angular velocities W1 and W2, one of which may be zero in the case of brake, are to be brought to the same speed by engaging the clutch or brake. Slippage occurs because the two elements are running at different speeds and energy is dissipated during actuation, resulting in a temperature rise. In analyzing the performance of these devices we shall be interested in the actuating force, the torque transmitted, the energy loss and the temperature rise. The torque transmitted is related to the actuating force, the coefficient of friction, and the geometry of the clutch or brake. This is problem in static, which will have to be studied separately for eath geometric configuration. However, temperature rise is related to energy loss and can be studied without regard to the type of brake or clutch because the geometry of interest is the heat-dissipating surfaces. The various types of clutches and brakes may be classified as fllows:
1. Rim type with internally expanding shoes
2. Rim type with externally contracting shoes
3. Band type
4. Disk or axial type
5. Cone type
6. Miscellaneous type
The analysis of all type of friction clutches and brakes use the same general procedure. The following step are necessary:
1. Assume or determine the distribution of pressure on the frictional surfaces.
2. Find a relation between the maximum pressure and the pressure at any point
3. Apply the condition of statical equilibrium to find (a) the actuating force, (b) the torque, and (c) the support reactions.
Miscellaneous clutches include several types, such as the positive-contact clutches, overload-release clutches, overrunning clutches, magnetic fluid clutches, and others.
A positive-contact clutch consists of a shift lever and two jaws. The greatest differences between the various types of positive clutches are concerned with the design of the jaws. To provide a longer period of time for shift action during engagement, the jaws may be ratchet-shaped, or gear-tooth-shaped. Sometimes a great many teeth or jaws are used, and they may be cut either circumferentially, so that they engage by cylindrical mating, or on the faces of the mating elements.
Although positive clutches are not used to the extent of the frictional-contact type, they do have important applications where synchronous operation is required.
Devices such as linear drives or motor-operated screw drivers must run to definite limit and then come to a stop. An overload-release type of clutch is required for these applications. These clutches are usually spring-loaded so as to release at a predetermined toque. The clicking sound which is heard when the overload point is reached is considered to be a desirable signal.
An overrunning clutch or coupling permits the driven member of a machine to “freewheel” or “overrun” because the driver is stopped or because another source of power increase the speed of the driven. This
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type of clutch usually uses rollers or balls mounted between an outer sleeve and an inner member having flats machined around the periphery. Driving action is obtained by wedging the rollers between the sleeve and the flats. The clutch is therefore equivalent to a pawl and ratchet with an infinite number of teeth.
Magnetic fluid clutch or brake is a relatively new development which has two parallel magnetic plates. Between these plates is a lubricated magnetic powder mixture. An electromagnetic coil is inserted somewhere in the magnetic circuit. By varying the excitation to this coil, the shearing strength of the magnetic fluid mixture may be accurately controlled. Thus any condition from a full slip to a frozen lockup may be obtained.
Introduction of Machining
Have a shape as a processing method, all machining process for the production of the most commonly used and most important method. Machining process is a process generated shape, in this process, Drivers device on the workpiece material to be in the form of chip removal. Although in some occasions, the workpiece under no circumstances, the use of mobile equipment to the processing, However, the majority of the machining is not only supporting the workpiece also supporting tools and equipment to complete.
Machining know the process has two aspects. Small group of low-cost production. For casting, forging and machining pressure, every production of a specific shape of the workpiece, even a spare parts, almost have to spend the high cost of processing. Welding to rely on the shape of the structure, to a large extent, depend on effective in the form of raw materials. In general, through the use of expensive equipment and without special processing conditions, can be almost any type of raw materials, mechanical processing to convert the raw materials processed into the arbitrary shape of the structure, as long as the external dimensions large enough, it is possible. Because of a production of spare parts, even when the parts and structure of the production batch sizes are suitable for the original casting, Forging or pressure processing to produce, but usually prefer machining.
Strict precision and good surface finish, Machining the second purpose is the establishment of the high precision and surface finish possible on the basis of. Many parts, if any other means of production belonging to the large-scale production, Well Machining is a low-tolerance and can meet the requirements of small batch production. Besides, many parts on the production and processing of coarse process to improve its general shape of the surface. It is only necessary precision and choose only the surface machining. For instance, thread, in addition to mechanical processing, almost no other processing method for processing. Another example is the blacksmith pieces keyhole processing, as well as training to be conducted immediately after the mechanical completion of the processing.
Primary Cutting Parameters
Cutting the work piece and tool based on the basic relationship between the following four elements to fully describe : the tool geometry, cutting speed, feed rate, depth and penetration of a cutting tool.
Cutting Tools must be of a suitable material to manufacture, it must be strong, tough, hard and wear-resistant. Tool geometry -- to the tip plane and cutter angle characteristics -- for each cutting process must be correct.
Cutting speed is the cutting edge of work piece surface rate, it is inches per minute to show. In order to effectively processing, and cutting speed must adapt to the level of specific parts -- with knives. Generally, the more hard work piece material, the lower the rate.
Progressive Tool to speed is
cut into the work piece speed. If the work piece or tool for rotating movement, feed rate per round over the number of inches to the measurement. When the work piece or tool for reciprocating movement and feed rate on each trip through the measurement of inches. Generally, in other conditions, feed rate and cutting speed is inversely proportional to。
Depth of penetration of a cutting tool -- to inches dollars -- is the tool to the work piece distance. Rotary cutting it to the chip or equal to the width of the linear cutting chip thickness. Rough than finishing, deeper penetration of a cutting tool depth.
Wears of Cutting Tool
We already have been processed and the rattle of the countless cracks edge tool, we learn that tool wear are basically three forms : flank wear, the former flank wear and V-Notch wear. Flank wear occurred in both the main blade occurred vice blade. On the main blade, shoulder removed because most metal chip mandate, which resulted in an increase cutting force and cutting temperature increase, If not allowed to check, That could lead to the work piece and the tool vibration and provide for efficient cutting conditions may no longer exist. Vice-bladed on, it is determined work piece dimensions and surface finish. Flank wear size of the possible failure of the product and surface finish are also inferior. In most actual cutting conditions, as the principal in the former first deputy flank before flank wear, wear arrival enough, Tool will be effective, the results are made unqualified parts.
As Tool stress on the surface uneven, chip and flank before sliding contact zone between stress, in sliding contact the start of the largest, and in contact with the tail of zero, so abrasive wear in the region occurred. This is because the card cutting edge than the nearby settlements near the more serious wear, and bladed chip due to the vicinity of the former flank and lost contact wear lighter. This results from a certain distance from the cutting edge of the surface formed before the knife point Ma pit, which is usually considered before wear. Under normal circumstances, this is wear cross-sectional shape of an arc. In many instances and for the actual cutting conditions, the former flank wear compared to flank wear light, Therefore flank wear more generally as a tool failure of scale signs. But because many authors have said in the cutting speed of the increase, Maeto surface temperature than the knife surface temperatures have risen faster. but because any form of wear rate is essentially temperature changes by the significant impact. Therefore, the former usually wear in high-speed cutting happen.
The main tool flank wear the tail is not processed with the work piece surface in contact, Therefore flank wear than wear along with the ends more visible, which is the most common. This is because the local effect, which is as rough on the surface has hardened layer, This effect is by cutting in front of the hardening of t
he work piece. Not just cutting, and as oxidation skin, the blade local high temperature will also cause this effect. This partial wear normally referred to as pit sexual wear, but occasionally it is very serious. Despite the emergence of the pits on the Cutting Tool nature is not meaningful impact, but often pits gradually become darker If cutting continued the case, then there cutter fracture crisis.
If any form of sexual allowed to wear, eventually wear rate increase obviously will be a tool to destroy failure destruction, that will no longer tool for cutting, cause the work piece scrapped, it is good, can cause serious damage machine. For various carbide cutting tools and for the various types of wear, in the event of a serious lapse, on the tool that has reached the end of the life cycle. But for various high-speed steel cutting tools and wear belonging to the non-uniformity of wear, has been found : When the wear and even to allow for a serious lapse, the most meaningful is that the tool can re-mill use, of course, In practice, cutting the time to use than the short time lapse. Several phenomena are one tool serious lapse began features : the most common is the sudden increase cutting force, appeared on the work piece burning ring patterns