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701 精密深孔加工扭振裝置設(shè)計【全套7張CAD圖+文獻(xiàn)翻譯+開題報告+說明書】,全套7張CAD圖+文獻(xiàn)翻譯+開題報告+說明書,701,精密深孔加工扭振裝置設(shè)計【全套7張CAD圖+文獻(xiàn)翻譯+開題報告+說明書】,精密,加工,裝置,設(shè)計,全套,cad,文獻(xiàn),翻譯,開題,報告,講演,呈文
精密深孔加工扭振裝置摘 要 振動鉆削是振動切削的一個分支,它與普通鉆削的區(qū)別在于鉆孔過程中通過振動裝置使鉆頭與工件之間產(chǎn)生可控的相對運(yùn)動。振動方式主要有三種,即軸向振動(振動方向與鉆頭軸線方向相同)、扭轉(zhuǎn)振動(振動方向與鉆頭旋轉(zhuǎn)方向相同)和復(fù)合振動(軸向振動與扭轉(zhuǎn)振動迭加)。其中,軸向振動易于實現(xiàn),工藝效果良好,在振動鉆削中占主導(dǎo)地位。振動的激勵方式主要有超聲波振動、機(jī)械振動、液壓振動和電磁振動。其中,超聲波振動的頻率通常在16以上,所以也稱為高頻振動鉆削;其它三種振動方式的頻率一般為幾百赫茲,故稱為低頻振動鉆削。振動鉆削改變了傳統(tǒng)鉆削的切削機(jī)理。在振動鉆削過程中,當(dāng)主切削刃與工件不分離(不分離型振動鉆削)時,切削速度、切削方向等參數(shù)產(chǎn)生周期性變化;當(dāng)主切削刃與工件時切時離(分離型振動鉆削)時,切削過程變成脈沖式的斷續(xù)切削。當(dāng)振動參數(shù)(振動頻率和振幅)、進(jìn)給量、主軸轉(zhuǎn)速等選擇合理時,可明顯提高鉆入定位精度及孔的尺寸精度、圓度和表面質(zhì)量,減小出口毛刺,降低切削力和切削溫度,延長鉆頭壽命。振動鉆削良好的工藝效果已引起國內(nèi)外研究者的普遍關(guān)注。關(guān)鍵詞:振動鉆削;電機(jī);帶傳動;偏心軸;主軸ABSTRACTVibration drilling is a branch of vibratory cutting, and it is the difference between ordinary drilling borehole process through the vibrating device bit with workpiece occurs between the relative motion of controllable. There are three main vibration mode, namely axial vibration (vibration direction and drill axis torsional vibration (same), with bits direction of vibration rotation direction the same) and complex vibration (axial vibration and torsional vibration superposition). Among them, the axial vibration easy to realize and good results, in process of vibration drilling dominant. The incentive ways mainly have the vibration ultrasonic vibration, mechanical vibration, hydraulic vibration and electromagnetic vibration. Among them, the ultrasonic vibration frequency usually 16kHz above, so in high frequency vibration drilling, also called; The other three vibration mode frequency general for hundreds of Hertz so called the low frequency vibration drilling. Vibration drilling has changed the traditional drilling cutting mechanism. In vibration drilling process, when the main cutting edge with workpiece are not isolated (not separated type vibration drilling), cutting speed, cutting parameters such as periodic changes direction produced; When the Lord when the cutting edges and workpiece when separated type cut from (vibration drilling), cutting process into pulsing concentres cutting. When the vibration parameters (vibration frequency and amplitude), feeding, reasonable selection of spindle speed etc, can obviously increase the penetration positioning accuracy and pore size precision, roundness and surface quality and reduce export burr, reduce the temperature of cutting force and cutting, prolong drill life. Good vibration drilling process effect by the domestic and international researchers already popular attention.Key words: vibration drilling; motor; Belt transmission; Eccentric shaft; spindle目 錄1 緒 論11.1 振動鉆削技術(shù)的發(fā)展歷史21.2 振動鉆削的機(jī)理12 裝置設(shè)計42.1 裝置總體方案42.2 電機(jī)的選擇62.3 帶傳動設(shè)計82.4 偏心軸及其附件設(shè)計122.5 主軸及其附件設(shè)計182.6 底板設(shè)計23參考文獻(xiàn)24致 謝25附 錄 26III1 緒論1.1 振動鉆削技術(shù)的發(fā)展歷史 孔加工是金屬切削加工中最常用的加工工藝。據(jù)統(tǒng)計,孔加工的金屬切除量約占切削加工總金屬切除量的1/3,鉆頭的產(chǎn)量約占刀具總產(chǎn)量的60%。目前用于加工微小孔的工藝方法雖然較多,但應(yīng)用最廣泛、生產(chǎn)實用性最強(qiáng)的仍是采用麻花鉆鉆削加工。隨著對孔加工質(zhì)量和效率的要求不斷提高,傳統(tǒng)的鉆削工藝已顯示出極大的局限性,而近年來迅速發(fā)展的振動鉆削工藝則日益顯示出其獨特的優(yōu)勢及廣闊的應(yīng)用前景。振動鉆削是振動切削的一個分支,它與普通鉆削的區(qū)別在于鉆孔過程中通過振動裝置使鉆頭與工件之間產(chǎn)生可控的相對運(yùn)動。振動方式主要有三種,即軸向振動(振動方向與鉆頭軸線方向相同)、扭轉(zhuǎn)振動(振動方向與鉆頭旋轉(zhuǎn)方向相同)和復(fù)合振動(軸向振動與扭轉(zhuǎn)振動迭加)。其中,軸向振動易于實現(xiàn),工藝效果良好,在振動鉆削中占主導(dǎo)地位。振動的激勵方式主要有超聲波振動、機(jī)械振動、液壓振動和電磁振動。其中,超聲波振動的頻率通常在16以上,所以也稱為高頻振動鉆削;其它三種振動方式的頻率一般為幾百赫茲,故稱為低頻振動鉆削。振動鉆削改變了傳統(tǒng)鉆削的切削機(jī)理。在振動鉆削過程中,當(dāng)主切削刃與工件不分離(不分離型振動鉆削)時,切削速度、切削方向等參數(shù)產(chǎn)生周期性變化;當(dāng)主切削刃與工件時切時離(分離型振動鉆削)時,切削過程變成脈沖式的斷續(xù)切削。當(dāng)振動參數(shù)(振動頻率和振幅)、進(jìn)給量、主軸轉(zhuǎn)速等選擇合理時,可明顯提高鉆入定位精度及孔的尺寸精度、圓度和表面質(zhì)量,減小出口毛刺,降低切削力和切削溫度,延長鉆頭壽命。振動鉆削良好的工藝效果已引起國內(nèi)外研究者的普遍關(guān)注,自1954年日本宇都宮大學(xué)的隈部淳一郎教授提出振動鉆削理論以來,各國學(xué)者對振動鉆削進(jìn)行了大量理論研究及實驗分析,取得了許多有價值的研究成果,其中一些成果已逐步應(yīng)用于加工領(lǐng)域。低頻振動切削技術(shù)目前已應(yīng)用于孔加工(包括鉆、擴(kuò)、鉸、鎖、攻絲等)和外圓車削加工等領(lǐng)域,解決實際生產(chǎn)中諸如切屑處理、改善切削加工性、提高加工質(zhì)量、延長刀具壽命等問題,理論上也獲得了許多發(fā)展。1.2 振動鉆削的機(jī)理振動切削是在普通切削過程中給刀具或工件人為地加上某種有規(guī)律的、可控的振動,從而形成在機(jī)理上不同于普通切削的切削方法.振動切削按振動頻率,可分為高頻振動切削超聲振動切削 和低頻振動切削f200Hz實踐證明,不論是高頻還是低頻振動切削,只要振動參數(shù)和切削用量選擇得當(dāng),都能產(chǎn)生普通切削所無法比擬的切削效果,如改善難加工材料的可加工性,可靠地斷屑、排屑,顯著減小切削力,降低切削溫度,降低表面粗糙度,提高切削液的使用效果,從而大大地提高刀具的耐用度尤其在難加工材料和精密零件的加工中,振動切削已成為一種不可忽視的加工方法.用麻花鉆進(jìn)行振動切削時,振動形式有扭振主切削方向上的振動 、軸向振動進(jìn)給方向上的振動和復(fù)合振動同時進(jìn)行扭振和軸向振動。一般認(rèn)為,當(dāng)鉆頭進(jìn)行扭振時,僅僅改變了切削速度,并沒有形成切削厚度的變化,因而,從運(yùn)動學(xué)上分析,在認(rèn)為刀具是剛性的條件下,扭振并無斷屑條件,對于復(fù)合振動中的扭振成分也是如此.但是,由于扭振是在鉆頭外緣部分的主切削方向上的振動,能起到減小切削力的作用;另一方面,它所產(chǎn)生的圓周方向上的切削速度的波動,與進(jìn)給運(yùn)動合成,仍然形成了切削厚度的變化,也有利于斷屑.軸向振動對鉆芯部分的切削刃而言,振動方向與切削方向一致,使橫刃部分的沖剪作用有規(guī)律地進(jìn)行,從而使作用在橫刃上的脈沖力發(fā)揮作用,這時,對鉆頭外緣附近的切削刃而言,就形成吃刀方向振動切削機(jī)理.另一方面,振動切削過程中,由于刀具與工件之間斷續(xù)接觸,使得切削溫度降低,正應(yīng)力減小,內(nèi)摩擦向外摩擦轉(zhuǎn)化,而且刀具的動態(tài)沖擊力產(chǎn)生了高于靜態(tài)剪應(yīng)力的波前剪切應(yīng)力,這些也是切削力降低,工件材料更容易被破壞的原因.鉆削工藝引入振動方式以后,由于受到振動、切削力、沖擊等互相作用,加工表面的各種參數(shù)呈周期性變化,切屑不像麻花鉆鉆出來呈帶狀的切屑,而是片狀、顆粒狀、線性狀等不同的形式。切屑原理分析:設(shè)由于施振系統(tǒng)的作用,刀頭產(chǎn)生振動為式中:1為振幅,為振動頻率(),為時間。刀頭的軸向位移()()= + (1)式中:為走刀量();為主軸轉(zhuǎn)速()。設(shè)為前后兩刀波紋的重迭系數(shù)=60=+ (2)式中:為整數(shù);01。設(shè) (3)當(dāng)0,即 (4)實現(xiàn)斷屑(理論上)。實驗證明,振動鉆削在加工過程中都能斷屑,其原理是刀具與工件進(jìn)行間歇、斷續(xù)的切削,所形成的切屑在切削力振動擠壓,沖擊負(fù)荷的周期變化的共同作用下形成斷裂,所以斷屑在振動鉆削加工中最易形成。2 裝置設(shè)計2.1 裝置總體方案精密深孔鉆削是機(jī)械加工中較難的問題,特別是在難加工材料上的鉆削小直徑深孔,難度更大。一般情況下,用槍鉆來加工小直徑深孔,雖然冷卻潤滑和排屑都有較大的改善,但斷屑并未解決。振動鉆削技術(shù)是一種新的鉆削方法,在小直徑深孔加工中能有效地斷屑,有利于深孔鉆削中排屑問題的解決。由于振動鉆削所具有的特點,國內(nèi)外已在許多難加工材料的鉆削中采用了振動鉆削。實現(xiàn)振動鉆削的關(guān)鍵之一是振動鉆削裝置。各種振動鉆削裝置所能產(chǎn)生的穩(wěn)定的振動參數(shù)差別很大,因此,在實用上都有一定的局限性。槍鉆是一種外排屑深孔鉆,其結(jié)構(gòu)如圖1所示。通常切屑是被由刀具孔內(nèi)流入切削區(qū)的高壓切削油沖出孔的。如果切屑為連續(xù)不斷的帶狀屑,即使增大供抽壓力也難以可靠地沖出切屑,因此導(dǎo)致扭斷刀頭或刀桿的現(xiàn)象,所以槍鉆加工深孔時的切屑處理主要是斷屑問題。圖1 鉆槍一般來說,振動裝置應(yīng)滿足下列一些要求:(1).單位功率要大,即在一定的功率下具有最小的輪廓尺寸,能夠滿足盡可能廣泛的工藝要求;(2).振動參數(shù)(頻率與振幅)最好能單獨無級調(diào)節(jié),可調(diào)范圍要盡可能大,以便使同一種振動裝置能滿足不同工種、不同工序的特殊需要;(3).頻率特性要穩(wěn)定,即要求受負(fù)載的影響越小越好;(4).振動部分的質(zhì)量要適當(dāng),即要求附加的振動部分質(zhì)量不會引起工藝系統(tǒng)的振動,以保證在切削過程中工藝系統(tǒng)能平穩(wěn)工作;(5).要有足夠長的使用壽命,振動裝置中的易損件要便于更換;(6).工作要平穩(wěn),噪聲要小;(7).結(jié)構(gòu)要簡單,制造要方便,要容易和現(xiàn)有機(jī)床配套使用,甚至成為通用的機(jī)床部件;(8).和執(zhí)行機(jī)構(gòu)的連接要簡便、可靠,若用螺紋一類的連接方式,必須采取防松措施。振動裝置的類型若按振動的能源分類,可分為強(qiáng)迫振動裝置和自激振動裝置。強(qiáng)迫振動裝置可根據(jù)實際需要,在一定范圍內(nèi)隨機(jī)改變振動參數(shù),它受切削過程的影響較小,在切削過程中容易維持振動參數(shù)的穩(wěn)定性,因此應(yīng)用最多。強(qiáng)迫振動切削裝置有機(jī)械、電磁、電氣、氣動和液壓等形式;也可以根據(jù)具體需要組成各種組合形式的振動裝置,如機(jī)械-液壓、電氣-液壓等。機(jī)械式振動裝置結(jié)構(gòu)簡單,造價低,使用和維護(hù)方便,切削過程中振動參數(shù)受負(fù)載影響較小,其結(jié)構(gòu)有偏心式、曲柄-滑塊式、四連桿機(jī)構(gòu)等。偏心式振動裝置由電動機(jī)、振動軸、偏心輪、偏心輪軸等組成。本人設(shè)計的是可用在車床上的低頻扭振裝置。為了使制造簡單方便,并考慮到工廠生產(chǎn)時加工工序比較固定,所以本裝置采用偏心量不可調(diào)的方案,取最常用的1mm作為偏心量。結(jié)合各種因素初步設(shè)計方案如下:在普通車床上,卸下刀架,在小溜板上安裝上機(jī)械式扭轉(zhuǎn)振動鉆削裝置。這種裝置由偏心式振動機(jī)構(gòu)、槍鉆、導(dǎo)向機(jī)構(gòu)和切削液循環(huán)系統(tǒng)等組成,車床主軸通過夾盤帶動工件作旋轉(zhuǎn)運(yùn)動(主運(yùn)動),偏心振動機(jī)構(gòu)帶動槍鉆作圓周方向振動(扭振),小溜板帶動槍鉆作軸向進(jìn)給運(yùn)動,高壓切削液通過槍鉆中心孔注入切削液,通過這種方法實現(xiàn)小徑深孔低頻扭振鉆削加工。如圖所示。電動機(jī)轉(zhuǎn)速為1,經(jīng)一級皮帶帶動偏心軸產(chǎn)生2轉(zhuǎn)速使偏心旋轉(zhuǎn),利用偏心軸軸端的偏心銷釘使擺桿上下擺動,擺桿與振動軸相連接,槍鉆夾持在振動軸的中心內(nèi),這樣槍鉆就在圓周方向以100/左右的振動頻率進(jìn)行扭振鉆削加工。調(diào)節(jié)槍鉆扭振頻率的方法:一是更換皮帶輪改變傳動比;二是采用調(diào)速電機(jī)實現(xiàn)無級調(diào)速。本裝置選用調(diào)速電機(jī)實現(xiàn)無級調(diào)速。圖2 偏心式振動裝置圖3 扭轉(zhuǎn)振動鉆削結(jié)構(gòu)件圖2.2 電機(jī)的選擇本裝置定為低頻扭振,所以取其振動頻率=0100設(shè)偏心軸轉(zhuǎn)速為n1 則由公式= (5)可算出n1=06000圖4 偏心軸與電機(jī)如上圖:中間軸為偏心軸,右端為電機(jī),它們之間用帶傳動,當(dāng)偏心軸以n1=06000 的速度高速旋轉(zhuǎn)時設(shè)電機(jī)轉(zhuǎn)速為n, 取帶傳動公比i=0.5由公式 (6)可得n=03000;調(diào)速電機(jī)有直流調(diào)速和交流調(diào)速兩大類。因為在工件加工時,主切削力由機(jī)床主軸提供,所以本裝置只是使夾持鉆頭的振動軸產(chǎn)生很微小的振動,所需功率很小。本著造價經(jīng)濟(jì),實用簡單的原則,查閱相關(guān)資料后,決定選用Z2-11型電機(jī)。該電機(jī)參數(shù)和樣本圖如下:型號:Z2-11額定功率:0.4kW額定電壓:220V額定電流:2.68A弱磁調(diào)速時最大轉(zhuǎn)速:3000 r/min效率:68%飛輪力矩:0.012 GD2/kgf.m2重量:30 kg圖5 Z2-11型電機(jī)表1 Z2-11型電機(jī)外形尺寸2.3 帶傳動設(shè)計帶傳動是由聯(lián)于主動軸上的帶輪1(主動輪),固聯(lián)于從動軸上的帶輪3(從動輪)和緊套在兩輪上的傳動帶2組成的(如圖)。當(dāng)原動機(jī)驅(qū)動主動輪轉(zhuǎn)動時,由于帶和帶輪間的摩擦(或嚙合),便拖動從動輪一起轉(zhuǎn)動,并傳遞一定動力。帶傳動具有結(jié)構(gòu)簡單,傳動平穩(wěn),造價低以及緩沖吸振等特點,在近代機(jī)械中被廣泛應(yīng)用。圖6 帶傳動示意圖(1) 確定計算功率計算功率Pca是根據(jù)傳遞的功率P,并考慮到載荷性質(zhì)和每天運(yùn)轉(zhuǎn)時間長短等因素的影響而確定的。即 (7)式中:計算功率,單位為kW; 傳遞的額定功率(如電動機(jī)的額定功率),單位為kW; 工作情況系數(shù)查相關(guān)資料,取 =1.3 則(2) 選擇帶型根據(jù)計算功率和主動輪轉(zhuǎn)速,查相關(guān)資料選用窄V帶SPZ(3) 確定帶輪的基準(zhǔn)直徑由于本裝置是用帶傳動增速,故主動輪為大帶輪,從動輪為小輪,已知傳動比=0.5,以結(jié)構(gòu)緊湊為指導(dǎo)原則,參考相關(guān)標(biāo)準(zhǔn),取主動輪125取從動輪67 驗算帶的速度=18.5 合理(4) 確定中心距a和帶的基準(zhǔn)長度初步估計中心距,由公式 (8)代入 =125 =67得 134 384取 =200 取定后,根據(jù)帶傳動的幾何關(guān)系,按下式計算所需的基準(zhǔn)長度 = (9)代入相關(guān)數(shù)值后,得= 705 參考相關(guān)標(biāo)準(zhǔn),取V帶基準(zhǔn)長度 =710 ,再根據(jù)來計算實際中心距。由于V帶傳動的中心距一般是可以調(diào)整的,故可采用下式作近似計算,即 (10) 代入數(shù)據(jù)得考慮安裝調(diào)整和補(bǔ)償預(yù)緊力的需要,中心距的變動范圍為:綜合考慮,取 = 210(5) 確定輪上的包角大于120度,合理(6) 確定V帶的根數(shù) (11) 式中:考慮包角不同時的影響系數(shù),簡稱包角系數(shù) 考慮帶的長度不同時的影響系數(shù),簡稱長度系數(shù) 單根V帶的基本額定功率計入傳動比的影響時,單根V帶額定功率的增量查表得:=0.96;=0.84;=2.15;=0.8;所以;=0.52/(2.15+0.8)X0.96X0.84因此取V帶根數(shù)=1(7) 確定帶的預(yù)緊力由公式: (12)查表 再代入其它已知的數(shù)據(jù),算得:(8) 計算帶傳動作用在軸上的力(簡稱壓軸力)由公式: (13)代入數(shù)據(jù)得 =92(9) V帶輪設(shè)計設(shè)計V帶輪時應(yīng)滿足的要求有:質(zhì)量?。唤Y(jié)構(gòu)工藝性好;無過大的鑄造應(yīng)力;質(zhì)量分布均勻;轉(zhuǎn)速高時要經(jīng)過動平衡;輪槽工作面要精細(xì)加工,以減小帶的磨損;各槽的尺寸和角度應(yīng)保持一定的精度,以使載荷分布較均勻等。帶輪材料可用鑄鐵,鑄鋼和鑄鋁。本裝置因帶輪轉(zhuǎn)速較高,故采用鑄鋼。由設(shè)計標(biāo)準(zhǔn):小輪結(jié)構(gòu)為實心式,大輪結(jié)構(gòu)為腹板式。它們的結(jié)構(gòu)圖如下所示: 圖7 實心式小V帶輪 圖8腹板式大V帶輪(10) V帶傳動的張緊裝置各種材質(zhì)的V帶都不是完全的彈性體,在預(yù)緊力的作用下,經(jīng)過一定時間的運(yùn)轉(zhuǎn)后,就會由于塑性變形而松弛,使預(yù)緊力F0降低。為了保證帶傳動的能力,應(yīng)定期檢查預(yù)緊力的數(shù)值。如發(fā)現(xiàn)不足時,必須重新張緊,才能正常工作。如下圖,電機(jī)安裝在滑槽上,張緊裝置為一焊在底板上的鋼塊,鋼塊上開有螺紋孔,裝上一螺栓后,調(diào)節(jié)螺栓即可調(diào)節(jié)電機(jī)的位置。 圖9 V帶傳動張緊裝置2.4 偏心軸及其附件設(shè)計.圖10 偏心軸及其附件偏心軸是本裝置最關(guān)鍵的零件,如上圖所示:在軸端偏心位置安裝有銷釘,當(dāng)V帶輪帶動該軸旋轉(zhuǎn)時,銷釘便以偏心軸中心線為中心作圓周運(yùn)動,其運(yùn)動軌跡的圓周半徑即是偏心量,V帶輪的固定方法是軸肩加螺母,整個軸在兩端裝上軸承后安裝在軸承座上。偏心軸轉(zhuǎn)速最高為6000 r/min,所以其制造精度要求較高。偏心軸的結(jié)構(gòu)圖如下:圖11 偏心軸的結(jié)構(gòu)圖軸的強(qiáng)度校核:偏心軸只受徑向力,主要是皮帶輪附加的壓軸力,由于偏心軸轉(zhuǎn)速較高,軸的微變形都會產(chǎn)生較顯著的影響,因此需要校核軸的剛度,因為軸的兩端用軸承支承,兩軸承間的軸部分無載荷,因此只需計算皮帶輪到其最近軸承上的部分軸的剛度。該軸段可簡化為下圖:圖12 偏心軸簡化圖選取坐標(biāo)系如圖所示,任意橫截面上的彎矩為M= -P(L-x)由公式 (14)得撓曲線的微分方程為積分得 (15) (16)在軸承端A,轉(zhuǎn)角和撓度均應(yīng)等于零,即當(dāng)x=0時=0=0把邊界條件代入公式(15),代入公式(16),得C=0D=0再將所得積分常數(shù)C和D代回2.11和2.12式,得轉(zhuǎn)角方程和撓曲線方程分別為 (17) (18)以截面B的橫坐標(biāo)x=L代入以上兩式,得截面B的轉(zhuǎn)角和撓度分別為= (19)= (20)為負(fù),表示截面B的轉(zhuǎn)角是順時針的。也為負(fù),表示B點的撓度下,令P=92N, E=210GPa, L=45mm, I=d4/64=7850mm4,得=-0.0000565=0.00167查資料驗證,剛度合格(1) 軸承的選用軸承的選取依據(jù)是:a 軸承的載荷,包括大小,方向和性質(zhì)b 軸承的轉(zhuǎn)速c 軸承的調(diào)心性能d 軸承的安裝和拆卸已知偏心軸只受徑向力,主要是V帶輪附加的壓軸力,該壓軸力為92N,軸的轉(zhuǎn)速最高為6000 r/min,偏心銷釘繞軸心線旋轉(zhuǎn)時以0100Hz的頻率與擺動桿碰撞,具有沖擊性質(zhì)。由偏心軸的工作性質(zhì),并按軸承的選用原則,參考相關(guān)的資料后,決定選用深溝球軸承。由相關(guān)資料,設(shè)軸承預(yù)期壽命 =30000 已知載荷=92N 轉(zhuǎn)速=6000 =3則所需軸承應(yīng)具有的基本額定動載荷C(單位為N)可根據(jù)公式計算得出: (20)代入數(shù)據(jù),算出=2034由軸承內(nèi)徑d ,基本額定動載荷C ,轉(zhuǎn)速n參考相關(guān)標(biāo)準(zhǔn)后選用深溝球軸承6204 標(biāo)準(zhǔn)摘自GB/T276-94 參照ISO-15-1981單位(mm)軸承代號: 6204尺寸d: 20尺寸D: 47尺寸B: 14額定動載荷C(kN): 10.0額定靜載荷C0(kN): 6.30極限轉(zhuǎn)速(rpm): 14000(脂潤滑) 18000(油潤滑)重量(kg): 0.098圖13 深溝球軸承6204(2) 軸承底座軸承座用來支承軸承和軸,要求剛度足夠,工作時穩(wěn)定振動小,軸承座一般是用鑄鐵鑄造,其中與軸承配合接觸的內(nèi)孔壁有較高的尺寸公差要求。偏心軸軸承座結(jié)構(gòu)圖如下:圖14 偏心軸軸承座結(jié)構(gòu)圖(3) 端蓋和透蓋為了阻止灰塵,水,酸氣和其它雜物進(jìn)入軸承,并阻止?jié)櫥瑒┝魇Ф匦鑼S承進(jìn)行密封,本裝置采用氈圈油封形式。具體方法是在軸承蓋上開出梯形槽,將毛氈按標(biāo)準(zhǔn)制成環(huán)形或帶形,放置在梯形槽中以與軸密合接觸。如下圖,透蓋是中間開有孔的軸承蓋,以使軸可以伸出來,孔壁上開有梯形槽,用來安放毛氈圈。端蓋是中間不通孔的軸承蓋,安裝在偏心軸不需伸出的另一端。它們都是使用鏍釘固定在軸承座上。圖15透蓋 圖16 端蓋(4) 偏心銷釘偏心銷釘選用槽銷,該類銷上輾壓或鍛出的三條縱向的溝槽,打入銷孔后與孔壁壓緊,不易松脫,能承受振動和變載荷,銷孔不需鉸制,可多次裝拆,一般用于有嚴(yán)重振動和沖擊載荷的場合。 圖17 槽銷2.5 主軸及其附件設(shè)計圖18 主軸及其附件主軸為一空心軸,如上圖,在右端利用軸肩和螺母將擺動桿固定在軸上,擺桿和軸之間通過鍵來傳遞力;軸的左端裝有彈性夾頭,可將鉆頭夾緊。當(dāng)偏心軸旋轉(zhuǎn)使擺桿繞主軸軸心線作微小往復(fù)扭轉(zhuǎn)時,整個主軸便帶動緊固在彈性夾頭上的鉆頭作扭轉(zhuǎn)運(yùn)動,即實現(xiàn)了本裝置所要求的扭振。(1) 主軸主軸上裝有鉆頭,鉆削加工時,鉆頭所受的扭矩要附加在主軸上,所以要求主軸具有足夠的扭轉(zhuǎn)強(qiáng)度。另外,為了保證加工時深孔的精度,對主軸的旋轉(zhuǎn)精度要求較高。主軸的結(jié)構(gòu)圖如下: 圖19 主軸結(jié)構(gòu)圖強(qiáng)度校核:由于鉆削時,鉆頭主要受軸向力和扭矩,軸向力對主軸的變形基本無影響,因此主軸只需校核扭轉(zhuǎn)強(qiáng)度。鉆削時,鉆頭所受扭矩 (20)設(shè)d0=8,=0.008 加工材料為中碳鋼,查資料:=0031; =2.0; =0.8 ; =1.0所以: M=9.81X0.031X8X2.0X0.008X0.8X1.0 =0.03 可見該扭矩很小,由于設(shè)計的主軸最小厚度已有11,遠(yuǎn)遠(yuǎn)能滿足扭轉(zhuǎn)強(qiáng)度要求。(2) 彈性夾頭彈性夾頭已有相關(guān)的設(shè)計標(biāo)準(zhǔn),本裝置所設(shè)計的彈性夾頭如下: 圖20 彈性夾頭 (材料:65Mn)(3) 軸承的選用主軸主要承受的是加工時工件對鉆頭的作用力,附加給軸承時主要是軸向力。軸向力 (21)查相關(guān)資料: ; ; ; = 1.0所以F=9.81X61.2X8X0.008X1.0X0.7X1.0= 26.9 由于振動鉆削時,所加工的孔一般都是小孔,因此鉆頭所受作用力都比較小,一般的軸承都可以滿足要求。由軸承選用規(guī)則確定選用圓錐滾子軸承,并根據(jù)主軸直徑查相關(guān)資料確定軸承型號最后選用圓錐滾子軸承30210 GB/T29794該軸承尺寸如下:圖21 軸承尺寸標(biāo)注表2 圓錐滾子軸承系列軸承型號外形尺寸Dimensions(mm)軸承重量新代號老代號DDTBCWeight(Kg)302107210E50.00090.00021.75020.00017.0000.563 額定動載荷C(kN):44.40額定靜載荷C0(kN):40.60極限轉(zhuǎn)速(rpm): 4300(脂潤滑) 5300(油潤滑)(4) 軸承座軸承座結(jié)構(gòu)圖如下:圖22 軸承座結(jié)構(gòu)圖(5) 夾緊螺母夾緊螺母是與彈性夾頭配合使用的,當(dāng)螺母往軸軸向擰進(jìn)時,螺母內(nèi)的斜面與彈性夾頭的外斜面緊緊貼合,同時螺母內(nèi)斜面對彈性夾頭外斜面施加一作用力,螺母越往里擰,這個作用力越大,彈性夾頭受這一作用力影響,便發(fā)生彈性形變以夾緊中心孔內(nèi)的鉆頭。夾緊螺母的結(jié)構(gòu)圖如下:圖23 加緊螺母結(jié)構(gòu)圖(6) 軸承蓋主軸兩端都要外伸,因此兩端的軸承蓋都為透蓋,使用毛氈圈作為密封件,具體介紹可參考偏心軸上的透蓋。(7) 擺桿擺桿為一中間開有滑槽的的長條塊,一端通過鍵與主軸聯(lián)接,另一端通過滑槽與偏心軸上的槽銷連接。圖24 擺桿2.6 底板設(shè)計電機(jī),偏心軸和主軸最后都要用螺栓安裝在底板上,這樣便成為了一個完整的裝置。電機(jī),偏心軸和主軸之間有相互位置關(guān)系。由于整個裝置最終是通過底板與機(jī)床固定,這便要求安裝時底板底面為一平整面,所以,用螺栓將主軸軸承座,偏心軸軸承座和電機(jī)固定在底板時,宜采用底部锪孔,將螺栓頭隱藏在底板內(nèi)。參考文獻(xiàn)1 濮良貴.紀(jì)名剛. 機(jī)械設(shè)計M. 第七版 高等教育出版社 2001年 1251972 劉鴻 材料力學(xué)M 第三版 高等教育出版社 2007 年 35583 馬曉湘.鐘均祥. 畫法幾何及機(jī)械制圖M 第二版 華南理工大學(xué)出版社 2000年1171254 上海電器科學(xué)研究所. 中小型電機(jī)產(chǎn)品樣本M 機(jī)械工業(yè)出版社 1994年27565 王光斗.王春福.機(jī)床夾具設(shè)計手冊M 上海科學(xué)技術(shù)出版社 1980年 1201406 楊黎明.黃凱.李恩至.陳仕賢.機(jī)械零件設(shè)計手冊 M 國防工業(yè)出版社1993 年 87957 張耀宸. 機(jī)械加工工藝設(shè)計實用手冊 M 航空工業(yè)出版社 1993年8 隈部淳一郎. 精密加工振動切削基礎(chǔ)與應(yīng)用 M 機(jī)械工業(yè)出版社 1985年 1792269 李祥林.薛萬夫.張日升. 振動切削及其在機(jī)械加工中的應(yīng)用 M 北京科技出版社 1985年 659810 姜大志.孫俊蘭. 振動切削技術(shù)與零件加工表面完整性工具技術(shù)J 200221(5)192211 姜大志.孫俊蘭.振動切削與加工表面完整性機(jī)械工藝師J.99(6)5812 楊曉輝.增澤隆久(日).采用工件加振方式的微細(xì)超聲加特性研究電加工與模具J. 2000(3)293213 黃德中.超聲波技術(shù)在機(jī)械工程中的利用現(xiàn)狀與最新發(fā)展振動與沖擊M.2002(3)747614 溫任林.顏景平.超聲波振動切削技術(shù)與誤差補(bǔ)償技術(shù)的綜合應(yīng)用工具技術(shù).199731(8)36致 謝附 錄附錄一:精密深孔加工扭振裝置裝配圖;附錄二:偏心軸零件圖;附錄三:主軸零件圖;附錄四:大軸承座圖;附錄五:小軸承座圖;附錄六:彈性夾頭圖;附錄七:底板圖;14外文原文Mechanical DesignAbstract:A machine is a combination of mechanisms and other components which transforms, transmits. Examples are engines, turbines, vehicles, hoists, printing presses, washing machines, and movie cameras. Many of the principles and methods of design that apply to machines also apply to manufactured articles that are not true machines. The term mechanical design is used in a broader sense than machine design to include their design. the motion and structural aspects and the provisions for retention and enclosure are considerations in mechanical design. Applications occur in the field of mechanical engineering, and in other engineering fields as well, all of which require mechanical devices, such as switches, cams, valves, vessels, and mixers.Keywords: Mechanical Design mechanisms Design ProcessThe Design ProcessDesigning starts with a need real.Existing apparatus may need improvements in durability, efficiency, weight, speed, or cost. New apparatus may be needed to perform a function previouslydone by men, such as computation, assembly, or servicing. With the objective wholly or partlyIn the design preliminary stage, should allow to design the personnel fully to display the creativity, not each kind of restraint. Even if has had many impractical ideas, also can in the design early time, namely in front of the plan blueprint is corrected. Only then, only then does not send to stops up the innovation the mentality. Usually, must propose several sets of design proposals, then perform the comparison. Has the possibility very much in the plan which finally designated, has used certain not in plan some ideas which accepts.When the general shape and a few dimensions of the several components become apparent, analysis can begin in earnest. The analysis will have as its objective satisfactory or superior performance, plus safety and durability with minimum weight, and a competitive cost. Optimum proportions and dimensions will be sought for each critically loaded section, together with a balance between the strengths of the several components. Materials and their treatment will be chosen. These important objectives can be attained only by analysis based upon the principles of mechanics, such as those of static for reaction forces and for the optimum utilization of friction; of dynamics for inertia, acceleration, and energy; of elasticity and strength of materials for stress and deflection; of physical behavior of materials; and of fluid mechanics for lubrication and hydrodynamic drives. The analyses may be made by the same engineer who conceived the arrangement of mechanisms, or, in a large company, they may be made by a separate analysis division or research group. Design is a reiterative and cooperative process, whether done formally or informally, and the analyst can contribute to phases other than his own. Product design requires much research and development. Many Concepts of an idea must be studied, tried, and then either used or discarded. Although the content of each engineering problem is unique, the designers follow the similar process to solve the problems. Product liability suits designers and forced in material selection, using the best program. In the process of material, the most common problems for five (a) dont understand or not use about the latest application materials to the best information, (b) failed to foresee and consider the reasonable use material may (such as possible, designers should further forecast and consider due to improper use products. In recent years, many products liability in litigation, the use of products and hurt the plaintiff accused manufacturer, and won the decision), (c) of the materials used all or some of the data, data, especially when the uncertainty long-term performance data is so, (d) quality control method is not suitable and unproven, (e) by some completely incompetent persons choose materials.Through to the above five questions analysis, may obtain these questions is does not have the sufficient reason existence the conclusion. May for avoid these questions to these questions research analyses the appearance indicating the direction. Although uses the best choice of material method not to be able to avoid having the product responsibility lawsuit, designs the personnel and the industry carries on the choice of material according to the suitable procedure, may greatly reduce the lawsuit the quantity. May see from the above discussion, the choice material people should to the material nature, the characteristic and the processing method have comprehensive and the basic understanding. Finally, a design based upon function, and a prototype may be built. If its tests are satisfactory, the initial design will undergo certain modifications that enable it to be manufactured in quantity at a lower cost. During subsequent years of manufacture and service, the design is likely to undergo changes as new ideas are conceived or as further analyses based upon tests and experience indicate alterations. Sales appeal.Some Rules for DesignIn this section it is suggested that, applied with a creative attitude, analyses can lead to important improvements and to the conception and perfection of alternate, perhaps more functional, economical,and durable products. To stimulate creative thought, the following rules are suggested for the designer and analyst. The first six rules are particularly applicable for the analyst.1. A creative use of need of physical properties and control process.2. Recognize functional loads and their significance.3. Anticipate unintentional loads.4. Devise more favorable loading conditions.5. Provide for favorable stress distribution and stiffness with minimum weight.6. Use basic equations to proportion and optimize dimensions.7. Choose materials for a combination of properties.8. Select carefully, stock and integral components.9. Modify a functional design to fit the manufacturing process and reduce cost.10. Provide for accurate location and noninterference of parts in assembly. Machinery design covers the following contents.1. Provides an introduction to the design process , problem formulation ,safety factors.2. Reviews the material properties and static and dynamic loading analysis ,Including beam , vibration and impact loading.3. Reviews the fundamentals of stress and defection analysis.4. Introduces fatigue-failure theory with the emphasis on stress-life approaches to high-cycle fatigue design, which is commonly used in the design of rotation machinery.5. Discusses thoroughly the phenomena of wear mechanisms, surface contact stresses ,and surface fatigue.6. Investigates shaft design using the fatigue-analysis techniques.7. Discusses fluid-film and rolling-element bearing theory and application8. Gives a thorough introduction to the kinematics, design and stress analysis of spu
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