凸輪分析作業(yè)演示教學(xué)

Ex.5-1Aplatecamwithpositive-offsettranslatingrollerfolloweristohavethefollowingmotion:arisethroughlifth=40mmwithasineaccelerationmotioncurveduring0=150,S=30,areturnwitha3-4-5polynomialmotioncurveduring0'=120,andS'=60.Thecamrotatesclockwise.Thegivendimensionsare:rP=40mm.rR=12mm,e=12mmandrC=25mm.Constructthepitchcurveandthecamcontourgraphicallywithascaleof1:1.Labelinredinkthecentrelineofthefollower,S,therollerandthepressureanglecorrespondingto=60and=0.第一頁，共67頁。Ex.5-1第二頁，共67頁。典型錯(cuò)誤：

1、偏置方向(fāngxiàng)錯(cuò)誤

2、不應(yīng)沿方向(fāngxiàng)作圖

3、基圓半徑=rprp+rr

4、偏置方向(fāngxiàng)突變

第三頁，共67頁。典型錯(cuò)誤(cuòwù)：

5、曲線連接不光滑

6、不應(yīng)沿徑向減rr得實(shí)際廓線的點(diǎn)

第四頁，共67頁。Ex.5-2AplatecamwithtranslatingoffsetrollerfollowerhasthesamemotioncurveanddimensionsasthoseinEx.5-1.Writeaprogramtocalculatetheco-ordinatesofthepitchcurve,thecamcontourandthelocusofthecentreofthemillingcutter,thepressureangle,andtheradiusBofcurvatureofthepitchcurve.第五頁，共67頁。Ex.5-3Fortheplatecamwithtranslatingoffsetrollerfollowerasshownbelow,arcsGHandIJaretwoarcswithcentreatO.IndicatetheradiusrPofprimecircle,offsete,camangle0forrise,camangleSforouterdwell,camangle0'forreturn,camangleS'forinnerdwellandlifth.Forthepositionshown,indicatepressureangle,displacementSandthecorrespondingcamangle.第六頁，共67頁。Ex.5-3第七頁，共67頁。根據(jù)(gēnjù)實(shí)際廓線求理論廓線第八頁，共67頁。擦掉實(shí)際廓線和滾子

H’I’J’G’分別是升程開始處遠(yuǎn)休止(xiūzhǐ)開始處回程開始處和近休止(xiūzhǐ)開始處.第九頁，共67頁。畫基圓和偏置(piānzhì)圓第十頁，共67頁。畫升程開始(kāishǐ)處遠(yuǎn)休止開始(kāishǐ)處回程開始(kāishǐ)處和近休止開始(kāishǐ)處的導(dǎo)桿中心線第十一頁，共67頁。畫全等三角形第十二頁，共67頁。求0第十三頁，共67頁。求s第十四頁，共67頁。求0’第十五頁，共67頁。求S’第十六頁，共67頁。求h第十七頁，共67頁。S和第十八頁，共67頁。Ex.5-3第十九頁，共67頁。Ex.5-4Fortheplatecamwithtranslatingoffsetrollerfollowerasshownbelow,arcsEA,ABandBCDarethreearcswithcentreatO,NandP,respectively.IndicatetheradiusrPofprimecircle,offsete,camangle0forrise,camangleSforouterdwell,camangle0'forreturn,camangleS'forinnerdwellandlifth.Forthepositionshown,indicatepressureangle,displacementSandthecorrespondingcamangle.第二十頁，共67頁。Ex.5-4第二十一頁，共67頁。根據(jù)實(shí)際(shíjì)廓線求理論廓線第二十二頁，共67頁。擦掉實(shí)際廓線和滾子

H’I’J’G’分別(fēnbié)是升程開始處遠(yuǎn)休止開始處回程開始處和近休止開始處.第二十三頁，共67頁。畫基圓和偏置(piānzhì)圓第二十四頁，共67頁。畫升程開始(kāishǐ)處回程開始(kāishǐ)處和近休止開始(kāishǐ)處的導(dǎo)桿中心線第二十五頁，共67頁。畫全等三角形第二十六頁，共67頁。求0第二十七頁，共67頁。求h第二十八頁，共67頁。求0’第二十九頁，共67頁。求S’第三十頁，共67頁。求S和第三十一頁，共67頁。求第三十二頁，共67頁。Ex.5-5AplatecamwithanoscillatingrollerfollowersimilartothatinFig.5-36oftextbookistohavethefollowingmotion:anangularliftMAX=20withasineaccelerationmotioncurveduring0=150,S=30,areturnwitha3-4-5polynomialmotioncurveduring0'=120andS'=60.Thegivendimensionsare:rP=40mm,LOA=80mm,LAB=76mm,rR=12mmandrC=16mm.Constructthepitchcurveandthecamcontourgraphicallywithascaleof1:1.LabelinredinktheframeOA,,centrelineABofthefollower,therollerandcorrespondingto=60and=0.第三十三頁，共67頁。Ex.5-5第三十四頁，共67頁。Ex.5-6AplatecamwithanoscillatingrollerfollowerhasthesamemotioncurveanddimensionsasthoseinEx.5-5.Writeaprogramtocalculatetheco-ordinatesofthepitchcurve,thecamcontourandthelocusofthecentreofthemillingcutter,thepressureangleandtheradiusBofcurvatureofthepitchcurve.第三十五頁，共67頁。Ex.5-7Fortheplatecamwithoscillatingrollerfollowerasshownbelow,arcsGHandIJaretwoarcswithcentreatO.IndicateradiusofprimecirclerP,camangleforrise0,camangleforouterdwellS,camangleforreturn0',camangleforinnerdwellS'andangularliftMAX.Forthepositionshown,indicatepressureangle,angulardisplacementoffollowerandthecorrespondingcamangle.

第三十六頁，共67頁。Ex.5-7第三十七頁，共67頁。Ex.5-7第三十八頁，共67頁。Ex.5-7第三十九頁，共67頁。Ex.5-7第四十頁，共67頁。Ex.5-7第四十一頁，共67頁。Ex.5-7第四十二頁，共67頁。Ex.5-7第四十三頁，共67頁。Ex.5-7第四十四頁，共67頁。Ex.5-7第四十五頁，共67頁。Ex.5-8Aplatecamwithatranslatingflat-facedfolloweristohavethefollowingmotion:arisethroughlifth=50mmwithasineaccelerationmotioncurveduring0=150,S=30,areturnwitha3-4-5polynomialmotioncurveduring0'=120andS'=60.Thecamrotatesclockwise.Thegivendimensionsare:rP=50mm.rC=20mm.Constructthepitchcurveandthecamcontourgraphicallywithascaleof1:1.Labelinredinkthefollowercentreline,S,theflatface,thetangentpointTbetweenthecamcontourandtheflatfaceandcorrespondingto=60and=0.第四十六頁，共67頁。第四十七頁，共67頁。Ex.5-9Aplatecamwithatranslatingflat-facedfollowerhasthesamemotioncurveanddimensionsasthoseinEx.5-8.Writeaprogramtocalculatetheco-ordinatesofthepitchcurve,thecamcontourandthelocusofthecentreofthemillingcutterandtheradiusTofcurvatureofthecamcontour.

第四十八頁，共67頁。第四十九頁，共67頁。第五十頁，共67頁。補(bǔ)全運(yùn)動(dòng)(yùndòng)規(guī)律第五十一頁，共67頁。第五十二頁，共67頁。5-9FortheplatecamwithtranslatingoffsetrollerfollowerasshowninFig.5-33,arcsGHandIJaretwoarcswithcentreatO.IndicaterP,e,0,S,0',S',andh.Forthepositionshown,indicate,Sandthecorresponding.

第五十三頁，共67頁。Therequiredparameterscannotbefoundwithoutthelocusoftherollercentrerelativetothecam,orthepitchcurve.Thepitchcurveandthecamcontouraretwoparallelcurvesfortheplatecamwithrollerfollower.Drawoffsetcircleandprimecircle.Note:rp=OH’OH.第五十四頁，共67頁。O、I、I’三點(diǎn)(sāndiǎn)共線。O、J、J’三點(diǎn)(sāndiǎn)共線。O、G、G’三點(diǎn)(sāndiǎn)共線。O、H、H’三點(diǎn)(sāndiǎn)共線。在理論廓線上，H’、I’、J’、G’分別對(duì)應(yīng)(duìyìng)于升程開始、升程結(jié)束、回程開始、回程結(jié)束。第五十五頁，共67頁。過H’、I’、J’、G’(不是過H、I、J、G)作偏置圓的切線(qiēxiàn)。I’I”=hOI’-OH’.在反轉(zhuǎn)過程中，滾子中心沿理論(lǐlùn)廓線從H’到I’、再到J’、再到G’、直至回到H’。第五十六頁，共67頁。第五十七頁，共67頁。BB’=S.第五十八頁，共67頁。常見錯(cuò)誤：

不畫理論廓線！

圓心角當(dāng)成(dānɡchénɡ)推程角

行程h沿徑向線求

偏置圓切線過實(shí)際廓線交接點(diǎn)

改變偏置方向第五十九頁，共67頁。5-16FortheplatecamwithoscillatingrollerfollowerasshowninFig.5-34,arcsGHandIJaretwoarcswithcentreatO.IndicaterP,0,S,0',S',andMAX.Forthepositionshown,indicatei,iandthecorrespondingi.第六十頁，共67頁。Therequiredparameterscannotbefoundwithoutthelocusoftherollercentrerelativetothecam,orthepitchcurve.Drawprimecircleandpivotcircle.Note:rpOH.第六十一頁，共67頁。O、H、H’三點(diǎn)共線(ɡònɡxiàn)。O、I、I’三點(diǎn)共線(ɡònɡ