清华大学机械原理英文 (1).ppt

Chap 10SchemeofMechanismsystem Chap 10 1ReviewDesignProcessChap 10 2DesignProcessofKinematicSchemeoftheMechanismSystem Chap 10 1DesignProcess ProblemDefinition Why What Which How Chap 10 2Designprocessofkinematicschemeofthemechanismsystem ProcessExample Designprocess WorkingPrincipleoftheMachineStep1 Gearcutting formcuttingandgeneratingcuttingSheettransmissionmachine Creation conclusion MotionformsanalysisStep2 Analyzeanddecomposethemotionwhichmachineneeds thinkoutthemotionforms Method imitation creation Creation conclusion TypesynthesisofthemechanismsStep3 Choose combineintoorcreatethemechanismsPrinciple satisfytherequirements choosemechanismsassimpleasitcanbe limitthesize choosesuitablekinematicpairs considerthedrivers gooddynamiccharacteristics beadjustable besafe Cooperationdesignstep4 Cooperationofthefunction timeandspace Toensurethecooperationofworkinglinks theworkingcyclediagramisdrawn Itisatimetablefortheactionsofalltheworkinglinks PrincipleMethodWorkingcyclediagram Principle OperationOrder sequenceofactions StepandcycleLayoutandnointerferenceEfficiencyandlessenergy Method WorkingcycleWorkingtimeoftheeachmechanismMotioncooperation 4 FillingLotion 1 Transmission 2 Rotationandintermittent 3 Translationupanddown Rectilinearworkingcyclediagram Circularworkingcyclediagram Rectangularcoordinateworkingcyclediagram Workingcyclediagram EvaluationStep6 IndexesofevaluationSystemfunctionWorkingperformanceDynamicperformanceEconomicperformanceStructure size weight complexityLayout Example Shapingmachine Workingprincipleofthemachine CuttingplainsMill 铣 Plane 刨 Grind 磨 Motionformsanalysis Twomainmotionsandrequirement 1 Cuttingcycle2 Feedingcycle3 AdjustmentofthesystemRelativereciprocatingmotionbetweenthecutterandtheworkpiece Thestrokeshouldbeadjustable thevelocityofthemotionshouldbeuniform Thefeedingmotioninthedirectionperpendiculartocuttingmotion Thefeedingmotionshouldbeadjustable Typesynthesisofthemechanisms CuttingmotionFeedingmotion Selectionofmechanismsforcutting Selectingfeedingmechanisms Cooperationdesign Dimensionalsynthesisofmechanisms Usethemethodswetaikedintheabovechapters Evaluation PrinciplesSystemfunctionWorkingperformanceDynamicperformanceEconomicperformanceStructure size weight complexityLayout Kinematicdiagramofthemechanisms Homework 某自动机采用一个电机驱动 经过减速后驱动输送带 转盘间歇分度机构 冲头2和卸料杆1完成对毛坯3的输送 定位 加工和卸料等工艺动作 理论生产率为20个 分 其工艺动作为 1 由输送带和转盘间歇分度机构将毛坯3送到平台4上 冲头2开始下行 2 经过0 8秒后冲头2接触毛坯3 又经过0 2秒后 冲头2将毛坯3压缩到指定的尺寸 停歇0 4秒后 冲头2开始快速返回 至原始位置 等待下一个循环 3 在冲头2开始返回的同时 卸料杆1亦开始动作 经