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商 丘
工學(xué)院
2015-JXLW
專業(yè)代碼-編號
附表12:理工類論文格式模板
(斜體字均作為格式說明用)
本科畢業(yè)論文(設(shè)計)
青飼料切割機設(shè)計
學(xué) 院
專 業(yè)
學(xué) 號
學(xué)生姓名
指導(dǎo)教師
提交日期
年 月 日
誠 信 承 諾 書
本人鄭重承諾和聲明:
我承諾在畢業(yè)論文撰寫過程中遵守學(xué)校有關(guān)規(guī)定,恪守學(xué)術(shù)規(guī)范,此畢業(yè)論文(設(shè)計)中均系本人在指導(dǎo)教師指導(dǎo)下獨立完成,沒有剽竊、抄襲他人的學(xué)術(shù)觀點、思想和成果,沒有篡改研究數(shù)據(jù),凡涉及其他作者的觀點和材料,均作了注釋,如有違規(guī)行為發(fā)生,我愿承擔(dān)一切責(zé)任,接受學(xué)校的處理,并承擔(dān)相應(yīng)的法律責(zé)任。
畢業(yè)論文(設(shè)計)作者簽名:
年 月 日
III
摘 要
青飼料切割機主要用于飼料原料切割,主要由電機、傳動裝置、動力裝置、切割裝置、出料裝置、機架。
本設(shè)計主要是針對綠色飼料切割機的設(shè)計。首先,通過切割綠色飼料的結(jié)構(gòu)和工作原理,分析,在此基礎(chǔ)上提出了程序的總體結(jié)構(gòu);然后,主要技術(shù)參數(shù)的選擇計算;然后,主要成分為設(shè)計和驗證;最后,通過AutoCAD圖形軟件繪制裝配圖的圖青飼料和切割機的主要部件。
通過這次設(shè)計,建設(shè)大學(xué)的專業(yè)知識,例如:、機械設(shè)計、材料力學(xué)、寬容和互換性和機械制圖,掌握機械產(chǎn)品設(shè)計方法和經(jīng)驗,利用AutoCAD軟件,在今后的工作生活具有重要的意義。
關(guān)鍵詞:青飼料,切割,絞龍,設(shè)計
ABSTRACT
The green fodder cutting machine is mainly used for cutting the green fodder raw material, which is mainly composed of a motor, a transmission device, a feeding device, a cutting device, a discharging device, a machine frame, etc..
This design mainly aims at the design of the green feed cutting machine. Firstly, through to green fodder cutting machine structure and principle were analyzed. This analysis is proposed based on the overall structure of the program; then, the main technical parameters were calculated to select; then, of the main parts were designed and checked. Finally, through the AutoCAD drawing software drawn green fodder cutting machine assembly and major parts of the map.
Through the design, the consolidation of the University of the professional knowledge, such as: mechanical principles, mechanical design, mechanics of materials, tolerance and interchangeability theories, mechanical drawing; master the design method of general machinery products and be able to skillfully use AutoCAD drawing software, for the future work in life is of great significance.
Key Words:Green feed, Cutting, Auger, Design
目 錄
摘 要 I
ABSTRACT II
1 引 言 1
1.1研究背景及意義 1
1.2青飼料切割機類型 1
1.3市場前景分析 2
2 系統(tǒng)設(shè)計 4
2.1方案設(shè)計 4
2.2工作原理分析 4
3 進料及切割裝置設(shè)計 5
3.1電機的選擇 5
3.2總體動力參數(shù)計算 5
3.2.1傳動比計算 5
3.2.2各軸的轉(zhuǎn)速 5
3.2.3各軸的輸入功率 6
3.2.4各軸的輸入轉(zhuǎn)矩 6
3.3 V帶傳動的設(shè)計 6
3.3.1 V帶的基本參數(shù)計算 6
3.3.2帶輪結(jié)構(gòu)的設(shè)計 8
3.4齒輪傳動設(shè)計 8
3.4.1選精度等級、材料和齒數(shù) 8
3.4.2按齒面接觸疲勞強度設(shè)計 9
3.4.3按齒根彎曲強度設(shè)計 10
3.4.4幾何尺寸計算 11
3.4.5驗算 11
3.5軸及軸承、鍵的設(shè)計 12
3.5.1尺寸與結(jié)構(gòu)設(shè)計計算 12
3.6切割刀的設(shè)計 13
3.6.1切割刀的基本結(jié)構(gòu)尺寸設(shè)計 13
3.6.2刀的安裝 16
3.7進料螺旋攪龍設(shè)計 17
4 出料裝置及機架的設(shè)計 19
4.1蝸桿減速機的選擇 19
4.2 V帶傳動設(shè)計 19
4.2.1 V帶的基本參數(shù)計算 19
4.2.2帶輪結(jié)構(gòu)的設(shè)計 21
4.3出料螺旋攪龍設(shè)計 21
4.4機架設(shè)計 22
結(jié) 論 24
致 謝 25
參考文獻 26
附 錄 27
Ⅲ
1 引言
1 引 言
1.1研究背景及意義
近兩年來,保證食品加工機械的情況下,模型如割草機,耙撿球機,青貯鍘草機,銷售大幅增長的捏合機和乳品機械等特別是,青貯切碎機在過去一年中,有一種情況農(nóng)業(yè)市場現(xiàn)階段我國農(nóng)產(chǎn)品的購買,貨源充足,沒有熱情。然而,據(jù)專家介紹,我國農(nóng)產(chǎn)品還遠不能滿足目前的市場需求。目前的主要障礙是不數(shù)農(nóng)產(chǎn)品,但技術(shù)上的障礙。
食品加工機是一種為基礎(chǔ)材料,建設(shè)現(xiàn)代農(nóng)業(yè),代表先進生產(chǎn)力的主要途徑,是提高生產(chǎn)率的國家政策的不斷出臺惠農(nóng)農(nóng)業(yè)市場,現(xiàn)階段我國農(nóng)產(chǎn)品的采購,豐度供應(yīng),沒有熱情。模型如割草機,耙撿球機,青貯鍘草機,銷售大幅增長的捏合機和乳品機械等,尤其是青貯切碎機在去年,有情況,據(jù)專家介紹,我國農(nóng)產(chǎn)品還遠不能滿足市場需求的現(xiàn)狀。當(dāng)前的主要問題不是數(shù)量的農(nóng)產(chǎn)品,但問題的技術(shù)性和實用性?;趯嶋H生產(chǎn)設(shè)計的一個小房子切割機青飼料,它結(jié)構(gòu)簡單,使用方便,價格實惠,能夠滿足大多數(shù)獨立。
1.2青飼料切割機類型
通過查閱資料,目前青飼料切割機主要如下四類:
(1)臥式切割機
圖1-1所示是最常見的臥式切割機,彎刀裝在主軸電機,通過電機的旋轉(zhuǎn)運動的刀切青飼料,缺點是不切料的右邊緣的塊莖,葉片砍刀的同時,能源消耗振動同樣重要。
(2)立式切割機
圖1-2所示是立式切割機,優(yōu)點是結(jié)構(gòu)緊湊,占用空間小,缺點與臥式切割機一樣,但能切割飼料的種類有限。
圖1-1 臥式切割機 圖1-2 立式切割機
(3)臥式輥筒切碎機
圖1-3所示是臥式輥筒破碎機,優(yōu)點是能很好切割塊莖,輥筒上的刀片拆卸也很方便,缺點是不能切割藤蔓類青飼料,所以他的使用也受到了很大的限制。
(4)臥式多功能切割機
圖1-4所示是臥式多功能切割機,優(yōu)點是即能切割藤蔓類,又能切割塊莖類,缺點是,該設(shè)計在為了完成切割塊莖的目的是,過多裝入轉(zhuǎn)動刀片,在拆卸刀片時,非常不便,并且過多的刀片也增加產(chǎn)品的成本。
圖1-3 臥式輥筒切碎機 圖1-4 臥式多功能切割機
1.3市場前景分析
經(jīng)過市場調(diào)研發(fā)現(xiàn)。很少有適合小型養(yǎng)殖場、專業(yè)戶和個體農(nóng)戶要求的小型青飼料切割機。并且這些青飲料切割機還具有以下缺點:
(1)大多數(shù)青飼料切割機只能單獨切割塊狀飼料或莖桿類物料;
(2)切割刀刃為直刃、切割剛度低、對多纖維莖桿的切割性能差;
(3)用手喂入莖桿婁物料安全性差;
(4)塊料切碎時切碎均勻度差;
故我們設(shè)計一種能滿足小型養(yǎng)殖場、專業(yè)戶和個體農(nóng)戶要求。切割性能好,操作安全的小型青飼料切割機。
23
2 系統(tǒng)設(shè)計
2 系統(tǒng)設(shè)計
2.1方案設(shè)計
根據(jù)上述青飼料切割機類型,本次設(shè)計的青飼料切割機采用如下結(jié)構(gòu):
圖2-1 青飼料切割機方案簡圖
2.2工作原理分析
工作時,青飼料從料斗投入后,首先在輸送螺旋的推動下向右進入切割滾筒進行切割。切碎的青飼料落入出料斗在輸送螺旋的推動下送出出料斗。
3 進料及切割裝置設(shè)計
3 進料及切割裝置設(shè)計
3.1電機的選擇
電機是標(biāo)準(zhǔn)件。因為工作腔,運動負(fù)荷穩(wěn)定,所以選擇通用系列全封閉自扇冷式三相異步電動機鼠籠。
市場調(diào)查的綠色飼料的選擇電機為Y100L1-4,其額定功率為2.2kW負(fù)載轉(zhuǎn)速1420r/min。
3.2總體動力參數(shù)計算
3.2.1傳動比計算
則:;
;
3.2.2各軸的轉(zhuǎn)速
1軸
2軸
滾筒
3.2.3各軸的輸入功率
1軸
2軸
滾筒
3.2.4各軸的輸入轉(zhuǎn)矩
電機軸
1軸
2軸
滾筒
整理列表
軸名
功率
轉(zhuǎn)矩
轉(zhuǎn)速
傳動比
電機軸
2.2
14.8
1420
1軸
2.112
35.51
568
2.5
2軸
2.028
28.99
668.2
0.85
3軸
1.948
155.9
119.33
5.6
3.3 V帶傳動的設(shè)計
3.3.1 V帶的基本參數(shù)計算
7)計算V帶的根數(shù):
,查《機械設(shè)計基礎(chǔ)》表13-3 得:
;
(2),查表得:;
(3)由查表得,包角修正系數(shù)
(4)由,與V帶型號A型查表得:
綜上數(shù)據(jù),得
取合適。
8)計算預(yù)緊力(初拉力):
根據(jù)帶型A型查《機械設(shè)計基礎(chǔ)》表13-1得:
9)計算作用在軸上的壓軸力:
其中為小帶輪的包角。
10)V帶傳動的主要參數(shù)整理并列表:
帶型
帶輪基準(zhǔn)直徑(mm)
傳動比
基準(zhǔn)長度(mm)
A
2.5
1600
中心距(mm)
根數(shù)
初拉力(N)
壓軸力(N)
723.5
2
246.11
2397.54
3.3.2帶輪結(jié)構(gòu)的設(shè)計
3.4齒輪傳動設(shè)計
3.4.1選精度等級、材料和齒數(shù)
3.4.2按齒面接觸疲勞強度設(shè)計
由設(shè)計計算公式進行試算,即
齒高
3.4.3按齒根彎曲強度設(shè)計
彎曲強度的設(shè)計公式為
大齒輪的數(shù)據(jù)大
5)設(shè)計計算
計算結(jié)果對比,模擬數(shù)字M的疲勞強度計算齒面接觸大于彎曲疲勞強度的計算模塊,模塊的根,有一個彎曲強度是可取的2.62,并圓整為標(biāo)準(zhǔn)值m=3mm,
按接觸強度算得的分度圓直徑
算出小齒輪齒數(shù) 取
大齒輪齒數(shù) 取
3.4.4幾何尺寸計算
1)計算分度圓直徑
2)計算中心距
3)計算齒寬寬度取35mm
3.4.5驗算
合適
序號
名稱
符號
計算公式及參數(shù)選擇
1
齒數(shù)
Z
20,112
2
模數(shù)
m
3mm
3
分度圓直徑
4
齒頂高
5
齒根高
6
全齒高
7
頂隙
8
齒頂圓直徑
9
齒根圓直徑
10
中心距
3.5軸及軸承、鍵的設(shè)計
3.5.1尺寸與結(jié)構(gòu)設(shè)計計算
1)軸上的功率P1,轉(zhuǎn)速n1和轉(zhuǎn)矩T1
,,
2)初步確定軸的最小直徑
先按式初步估算軸的最小直徑。選取軸的材料45鋼,調(diào)質(zhì)處理。根據(jù)機械設(shè)計表11.3,取,于是得:
對于6208型深溝球軸承,由手冊中查得a=15mm。因此,軸的支撐跨距為L1=72mm。
根據(jù)計算做圖軸彎矩和扭矩圖的樹圖結(jié)構(gòu)板的彎曲和扭轉(zhuǎn)的C部分是危險截面的軸。先計算出截面C處的MH、MV及M的值列于下表。
載荷
水平面H
垂直面V
支反力F
,
,
C截面彎矩M
總彎矩
扭矩
3)按彎扭合成應(yīng)力校核軸的強度
根據(jù)式(15-5)及上表中的數(shù)據(jù),以及軸單向旋轉(zhuǎn),扭轉(zhuǎn)切應(yīng)力,取,軸的計算應(yīng)力
已選定軸的材料為45Cr,調(diào)質(zhì)處理。由表15-1查得。因此,故安全。
4)鍵的選擇
采用圓頭普通平鍵A型(GB/T 1096—1979)連接,聯(lián)接大帶輪的平鍵截面,。齒輪與軸的配合為,滾動軸承與軸的周向定位是過渡配合保證的,此外選軸的直徑尺寸公差為。
3.6切割刀的設(shè)計
3.6.1切割刀的基本結(jié)構(gòu)尺寸設(shè)計
所謂的切割、材料力學(xué)法克服內(nèi)部的凝聚力,是規(guī)范和分塊,片,絲,操作方法和產(chǎn)品形式的黃油。切割機運動必須滿足兩個條件得到滿足,切削工具,另一種是“供給”的材料。材料的進給運動,刀具相對運動的接觸。
(1)切刀材料
通常是鋼或碳鋼熱處理工具T9。這種選擇T9工具鋼
(2)對切刀的要求
一個好的(或切割刀)必須滿足以下要求:
切割質(zhì)量高、功耗低、結(jié)構(gòu)緊湊,性能穩(wěn)定,安全可靠,易于銳化,維修方便。
(3)選用或設(shè)計刀片時應(yīng)滿足的要求
在設(shè)計和選擇刀片必須滿足以下三個方面:材料,即現(xiàn)在的功率,保證切割;切割阻力矩小,均勻。
(4)刀片刃口幾何形狀及常用刀片形狀
刀具的刀刃的線性和幾何曲線,如圖3所示。
圖3-1 各幾何形狀刀刃
在本次設(shè)計中選用(c)外曲線刃口刀 進行滑切。
(5)刀的滑切與正切分析
切割機工作,工作方法的尺寸和功耗和切刀的刀片的特征參數(shù)有關(guān)的操作,滑動和切線切割。當(dāng)工作滑切,切割阻力小,易于切割,在切割省力,能耗低。當(dāng)?shù)对谇泄ぷ?,耐切割,切割困難,消耗功率。下面僅討論工具滑切原理。
圖3-2為切刀滑切示意圖。
圖 3-2 切刀滑切示意圖
圖 3-3 滑切省力原理圖
圖 3-4 不同鉗住角的物料受力分析圖
圖3-4中AB為動刀片刃口,CD為定刀片刃口,夾角為動、定刀片對物料的鉗住角,
圖 3-5 刀與料的相對位置圖
3.6.2刀的安裝
曲線動刀片A、B通過螺栓1、2、3、4安裝在刀盤P上,通過調(diào)節(jié)螺栓1、2、3、4來調(diào)整動刀片與定刀片的間隙。具體如下圖5-6所示。
圖 3-6 切刀簡圖
1、4.六角螺栓 2、3。 沉頭螺栓
3.7進料螺旋攪龍設(shè)計
式中:h---螺旋節(jié)距[m];
ns---螺旋轉(zhuǎn)速[r/min];
螺距h通常為:h1=k1D
式中:k1---螺旋節(jié)距與螺旋直徑的比值,與青飼料性質(zhì)有關(guān),通常取k1=0.7~1,對于摩擦系數(shù)大的青飼料,取小值(k1=0.7~0.8);對于流動性較好,易流散的青飼料,可取k1=1。
表4-5傾斜修正系數(shù)c
傾斜角β
0°
≤5°
≤10°
≤15°
≤20°
c
1.00
0.90
0.80
0.70
0.65
將上式結(jié)合起來,則有:Q=47ψck1D3nsρ,即:
(1)螺旋直徑
根據(jù)設(shè)計要求該攪龍直徑選用280mm,即:D=280mm
(2)螺距
取h1=(0.5~0.6)D=140~168mm,所以螺距為160mm。
(3)軸徑
d=(0.2~0.35)D,取d=0.2D=0.15×280=42mm,所以軸徑為42mm。
(3)篩筒設(shè)計
篩筒為圓筒形,篩孔直徑為15—20mm。材料用薄不銹鋼板制造。
4 出料裝置及機架設(shè)計
4 出料裝置及機架的設(shè)計
4.1蝸桿減速機的選擇
出料攪龍轉(zhuǎn)速不宜過高,本次取25r/min,因此選用傳動比為:29,中心距為80的蝸桿減速器。
4.2 V帶傳動設(shè)計
4.2.1 V帶的基本參數(shù)計算
對于A型帶選用
(3)實際中心距:
6)驗算主動輪上的包角:
由
得
其中為小帶輪的包角。
10)V帶傳動的主要參數(shù)整理并列表:
帶型
帶輪基準(zhǔn)直徑(mm)
傳動比
基準(zhǔn)長度(mm)
A
2
1000
中心距(mm)
根數(shù)
初拉力(N)
壓軸力(N)
212
2
246.11
2397.54
4.2.2帶輪結(jié)構(gòu)的設(shè)計
1)帶輪的材料:
采用鑄鐵帶輪(常用材料HT200)
2)帶輪的結(jié)構(gòu)形式:
V帶輪的結(jié)構(gòu)形式與V帶的基準(zhǔn)直徑有關(guān)。小帶輪接電動機,較小,所以采用實心式結(jié)構(gòu)帶輪。
4.3出料螺旋攪龍設(shè)計
表4-5立式混料機傾斜修正系數(shù)c
傾斜角β
0°
≤5°
≤10°
≤15°
≤20°
c
1.00
0.90
0.80
0.70
0.65
圖3-2 不同充填系數(shù)時青飼料層堆積情況及其滑移面
將上式結(jié)合起來,則有:Q=47ψck1D3nsρ
即:
(1)螺旋直徑
根據(jù)設(shè)計要求該立式混合機攪龍直徑選用100mm,即:D=100mm
(2)螺距
h1=D,取h1=(1.5~2)D=150~200mm,所以螺距為180mm。
(3)軸徑
d=(0.2~0.35)D,取d=0.24D=0.24×100=24mm,所以軸徑為24mm。
4.4機架設(shè)計
主要角色的底盤部件的安裝和所有其他的人。為了降低成本,一個完整的框架,連接件通過焊接與螺栓。根據(jù)設(shè)計要求,主要包括邊框焊接在鋼板加固由梁部分角鋼等。焊接時,主要致力于加強鐵位置與機架焊接,同時確保不出現(xiàn)夾渣、裂紋等機架材料主要是5毫米厚角鋼1435毫米×100毫米大小,采用等離子切割A(yù)P非常成型、沖壓等加工手段。分別加強板,加強抗機架連接方式,加強板的左側(cè)和右側(cè)的底盤是螺栓連接,在一個框架和加強板的加工過程中,在其位置上的螺栓連接孔的一些技術(shù)要求。支架之間的光束角大約是固定的,固定的方法焊接,因為該軸流脫粒的工作環(huán)境,為山區(qū),丘陵和處理,確保運輸安全人員,為保證焊接R焊接的焊接工藝要求,要求不能有渣,沒有裂紋等缺陷組裝完成框架,暴露的表面刷防銹漆。
結(jié)論
結(jié) 論
設(shè)計是一個回顧大學(xué)的知識,綜合運用過的知識的能力,獨立思考我們的獨立,解決技術(shù)問題的能力、繪圖、理論知識手冊中的加工生產(chǎn),甚至研究學(xué)習(xí)很多知識,但沒有機會使用和掌握這些東西。通過這種做法,我設(shè)計的機械設(shè)計過程的全面理解,計算能力和整體設(shè)計的訓(xùn)練和提高,而且我興趣坡你的機器更強大,更堅定了我的信心在工業(yè)開始設(shè)計網(wǎng)站,去圖書館,我下載了許多文獻中,綠色飼料切割機上的理解,然后開始準(zhǔn)備我的開題報告,任務(wù)書和預(yù)覽該方法的總體結(jié)構(gòu)的設(shè)計,我也遇到了很多困難,經(jīng)過多次修改的數(shù)據(jù)在總體方案確定,開始畫畫。在設(shè)計過程中得到老師的幫助,我認(rèn)為在交際的過程中,在老師的幫助下,我能學(xué)習(xí)牛津大學(xué)出版社的東西,老師從另一個角度的靈感,我給了我很大的幫助,鼓勵和設(shè)計的這段時間里,我基本上是按設(shè)計要求的綠色飼料切割機,但因為我的知識水平是有限的,不有沒有工作實踐經(jīng)驗,本設(shè)計中關(guān)鍵不足,請老師和同學(xué)提出寶貴的意見,以正確的時間。當(dāng)然,我知道所有的設(shè)計還沒有結(jié)束,因為我們需要防守,而且防御問題和老師的意見,我的畢業(yè)設(shè)計終于可以結(jié)束了。因此,我我還需要繼續(xù)努力,認(rèn)真準(zhǔn)備辯護,檢查我的論文,提高一個滿意的結(jié)論畫在我的大學(xué)。
25
致謝
致 謝
大學(xué)生活即將結(jié)束,在四年里,讓我遇見了許多熱心的幫助,工作階段的學(xué)習(xí)嚴(yán)格的老師。從成功的完成他們的畢業(yè)設(shè)計也不幫助和導(dǎo)師的精心指導(dǎo),在這里我對所有本畢業(yè)設(shè)計提供指導(dǎo)和幫助的老師和同學(xué)表示衷心的感謝。
首先,本設(shè)計的主教練,表示衷心的感謝。在他的努力,時間總是找到時間來照顧我們的領(lǐng)導(dǎo)人,進展,我們敦促我們學(xué)習(xí)。在整個設(shè)計過程中,老師,一個鏈接的網(wǎng)站實際借款,表明了,我不僅學(xué)到了書本,學(xué)習(xí)操作方法,我知道如何使用的關(guān)鍵,如何在合理的時間內(nèi),文檔和發(fā)射,在設(shè)計的過程中,她是我們的設(shè)計問題解決了。
其次,我們必須提供幫助,這樣的設(shè)計,教師和學(xué)生,真誠的感謝,在設(shè)計的過程中,他們給了我很多的幫助和無私的關(guān)懷,更重要的是,我們提供的技術(shù)資料,非常感謝他們,沒有這些文件數(shù)據(jù)是不完整的。
另外,我感謝所有的同學(xué)。
總之,本設(shè)計是相互作用的結(jié)果,教師和學(xué)生設(shè)計完成的,一個月很愉快,我們合作的大教堂,和真理,這就是我的生活,我的財富,給我?guī)椭睦蠋熀蛯W(xué)生,謝謝!
參考文獻
參考文獻
[1] 潘樹良.小型爪式粉碎機常見故障[J].農(nóng)機具之友,2007,(03)
[2] 段長勇等.發(fā)展飼料玉米優(yōu)化農(nóng)牧業(yè)結(jié)構(gòu).[J].飼料與畜牧.2010,(1):28~29.
[3] 王三民.機械原理與設(shè)計[M].北京.機械工業(yè)出版社.2001.
[4] 機械設(shè)計手冊編委會.機械設(shè)計手冊[M].北京.機械工業(yè)出版社.2004.
[5] 食品工業(yè)與設(shè)備[M].中國輕工業(yè)出版社,2000.
[6] 王三民主編.機械原理與課程設(shè)計[M].北京:機械工業(yè)出版社,2004.
[7] 成大先主編.機械設(shè)計手冊(單行本)[減(變)速器.電機與電器][M].北京:化學(xué)工業(yè)出版社,2004.
[8] 王世剛主編.機械設(shè)計實踐[M].哈爾濱:哈爾濱工程大學(xué)出版社,2003.
[9] 成大先主編.機械設(shè)計手冊(單行本)[機械傳單][M].北京:化學(xué)工業(yè)出版社,2004.
[10] 王三民.諸問俊主編.機械原理與設(shè)計[M].北京:機械工業(yè)出版社,2000.
[11] 劉品主編.機械精度設(shè)計與檢測基礎(chǔ)[M].哈爾濱:哈爾濱工業(yè)出版社,2004.
[12] 工程制圖基礎(chǔ)/武漢理工大學(xué)等五院?!豆こ讨茍D基礎(chǔ)》編寫組編[M].北京.高等教育出版社,2003.
[13]農(nóng)產(chǎn)品加工機械[M].長沙.湖南科技出版社.2002.
[14] Doughty S.mechanics of Machines.New York:Johh Wiley &Sons Inc,2010.3
[15] Jensen P. W.Classical and Modern Mechanisms for Engineers and Inventors.New York:Marcel Dekker,2012.3
41
附錄
附 錄
Basic Machining Operations and Cutting Technology
Basic Machining Operations
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.
Speed and Feeds in Machining
Speeds, feeds, and depth of cut are the three major variables for economical machining. Other variables are the work and tool materials, coolant and geometry of the cutting tool. The rate of metal removal and power required for machining depend upon these variables.
The depth of cut, feed, and cutting speed are machine settings that must be established in any metal-cutting operation. They all affect the forces, the power, and the rate of metal removal. They can be defined by comparing them to the needle and record of a phonograph. The cutting speed (V) is represented by the velocity of- the record surface relative to the needle in the tone arm at any instant. Feed is represented by the advance of the needle radially inward per revolution, or is the difference in position between two adjacent grooves. The depth of cut is the penetration of the needle into the record or the depth of the grooves.
Turning on Lathe Centers
The basic operations performed on an engine lathe are illustrated. Those operations performed on external surfaces with a single point cutting tool are called turning. Except for drilling, reaming, and lapping, the operations on internal surfaces are also performed by a single point cutting tool.
All machining operations, including turning and boring, can be classified as roughing, finishing, or semi-finishing. The objective of a roughing operation is to remove the bulk of the material as rapidly and as efficiently as possible, while leaving a small amount of material on the work-piece for the finishing operation. Finishing operations are performed to obtain the final size, shape, and surface finish on the workpiece. Sometimes a semi-finishing operation will precede the finishing operation to leave a small predetermined and uniform amount of stock on the work-piece to be removed by the finishing operation.
Generally, longer workpieces are turned while supported on one or two lathe centers. Cone shaped holes, called center holes, which fit the lathe centers are drilled in the ends of the workpiece-usually along the axis of the cylindrical part. The end of the workpiece adjacent to the tailstock is always supported by a tailstock center, while the end near the headstock may be supported by a headstock center or held in a chuck. The headstock end of the workpiece may be held in a four-jaw chuck, or in a type chuck. This method holds the workpiece firmly and transfers the power to the workpiece smoothly; the additional support to the workpiece provided by the chuck lessens the tendency for chatter to occur when cutting. Precise results can be obtained with this method if care is taken to hold the workpiece accurately in the chuck.
Very precise results can be obtained by supporting the workpiece between two centers. A lathe dog is clamped to the workpiece; together they are driven by a driver plate mounted on the spindle nose. One end of the Workpiece is mecained;then the workpiece can be turned around in the lathe to machine the other end. The center holes in the workpiece serve as precise locating surfaces as well as bearing surfaces to carry the weight of the workpiece ?and to resist the cutting forces. After the workpiece has been removed from the lathe for any reason, the center holes will accurately align the workpiece back in the lathe or in another lathe, or in a cylindrical grinding machine. The workpiece must never be held at the headstock end by both a chuck and a lathe center. While at first thought this seems like a quick method of aligning the workpiece in the chuck, this must not be done because it is not possible to press evenly with the jaws against the workpiece while it is also supported by the center. The alignment provided by the center will not be maintained and the pressure of the jaws may damage the center hole, the lathe center, and perhaps even the lathe spindle. Compensating or floating jaw chucks used almost exclusively on high production work provide an exception to the statements made above. These chucks are really work drivers and cannot be used for the same purpose as ordinary three or four-jaw chucks.
While very large diameter workpieces are sometimes mounted on two centers, they are preferably held at the headstock end by faceplate jaws to obtain the smooth power transmission; moreover, large lathe dogs that are adequate to transmit the power not generally available, although they can be made as a special. Faceplate jaws are like chuck jaws except that they are mounted on a faceplate, which has less overhang from the spindle bearings than a large chuck would have.
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 machini
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