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首页 good气缸的工作原理

good气缸的工作原理.doc

good气缸的工作原理

小绿逆
2017-10-22 0人阅读 举报 0 0 0 暂无简介

简介:本文档为《good气缸的工作原理doc》,可适用于综合领域

good气缸的工作原理第十三章气动执行元件和控制元件气动执行元件是一种能量转换装置它是将压缩空气的压力能转化为机械能驱动机构实现直线往复运动、摆动、旋转运动或冲击动作。气动执行元件分为气缸和气马达两大类。气缸用于提供直线往复运动或摆动输出力和直线速度或摆动角位移。气马达用于提供连续回转运动输出转矩和转速。气动控制元件用来调节压缩空气的压力流量和方向等以保证执行机构按规定的程序正常进行工作。气动控制元件按功能可分为压力控制阀、流量控制阀和方向控制阀。第一节气缸一、气缸的工作原理、分类及安装形式气缸的典型结构和工作原理图,普通双作用气缸、,缓冲柱塞,活塞,缸筒,导向套,防尘圈,前端盖,气口,传感器,活塞杆,耐磨环,密封圈,后端盖,缓冲节流阀以气动系统中最常使用的单活塞杆双作用气缸为例来说明气缸典型结构如图,所示。它由缸筒、活塞、活塞杆、前端盖、后端盖及密封件等组成。双作用气缸内部被活塞分成两个腔。有活塞杆腔称为有杆腔无活塞杆腔称为无杆腔。当从无杆腔输入压缩空气时有杆腔排气气缸两腔的压力差作用在活塞上所形成的力克服阻力负载推动活塞运动使活塞杆伸出当有杆腔进气无杆腔排气时使活塞杆缩回。若有杆腔和无杆腔交替进气和排气活塞实现往复直线运动。气缸的分类气缸的种类很多一般按气缸的结构特征、功能、驱动方式或安装方法等进行分类。分类的方法也不同。按结构特征气缸主要分为活塞式气缸和膜片式气缸两种。按运动形式分为直线运动气缸和摆动气缸两类。气缸的安装形式气缸的安装形式可分为)固定式气缸气缸安装在机体上固定不动有脚座式和法兰式。)轴销式气缸缸体围绕固定轴可作一定角度的摆动有U形钩式和耳轴式。)回转式气缸缸体固定在机床主轴上可随机床主轴作高速旋转运动。这种气缸常用于机床上气动卡盘中以实现工件的自动装卡。)嵌入式气缸气缸缸筒直接制作在夹具体内。二、常用气缸的结构原理普通气缸包括单作用式和双作用式气缸。常用于无特殊要求的场合。图,为最常用的单杆双作用普通气缸的基本结构气缸一般由缸筒、前后缸盖、活塞、活塞杆、密封件和紧固件等零件组成。andduediligenceevaluationsarticlendheadoffice,branch(jurisdiction),riskmanagement,marketingmanagementbranchwithintheDepartment'screditdoubleimplementationofinvestigationssystem:practicalimplementationofdoublesystem(E)othersupervisionandinspectionofthecontentsthduediligenceevaluationofficesandbranches(jurisdiction),riskmanagement,MarketingManagementDepartmentagreedtocarryoutpreloaninvestigationsupervisionandinspectionwork,evaluatewhetherinvestigatorsduediligencetodeterminewhethertheexemptionshouldbeInvestigatorsshouldbecompatiblewithDuediligenceassessmentshouldbebasedonthefactthat,followingtheprinciplesofobjectivity,impartialityandfairnessArticlethhead缸筒与前后缸盖固定连接。有活塞杆侧的缸盖为前缸盖缸底侧的缸盖为后缸盖。在缸盖上开有进排气通口有的还设有气缓冲机构。前缸盖上设有密封圈、防尘圈同时还设有导向套以提高气缸的导向精度。活塞杆与活塞紧固相连。活塞上除有密封圈防止活塞左右两腔相互漏气外还有耐磨环以提高气缸的导向性带磁性开关的气缸活塞上装有磁环。活塞两侧常装有橡胶垫作为缓冲垫。如果是气缓冲则活塞两侧沿轴线方向设有缓冲柱塞同时缸盖上有缓冲节流阀和缓冲套当气缸运动到端头时图,普通双作用气缸,弹簧挡圈,防尘圈压板,防尘圈,导向套,杆侧端盖,活塞杆,缸筒,缓冲垫,活塞,活塞密封圈,密封圈,耐磨环,无杆侧端盖缓冲柱塞进入缓冲套气缸排气需经缓冲节流阀排气阻力增加产生排气背压形成缓冲气垫起到缓冲作用。特殊气缸图,薄膜气缸,缸体,膜片,膜盘,活塞杆为了满足不同的工作需要在普通气缸的基础上通过改变或增加气缸的部分结构设计开发出多种特殊气缸。()薄膜式气缸图,为膜片气缸的工作原理图。膜片有平膜片和盘形膜片两种一般用夹织物橡胶、钢片或磷青铜片制成厚度为,mm(有用,mm厚膜片的)。图,所示的膜片气缸的功能类似于弹簧复位的活塞式单作用气缸工作时膜片在压缩空气作用下推动活塞杆运动。它的优点是:结构简单、紧凑、体积小、重量轻、密封性好、不易漏气、加工简单、成本低、无磨损件、维修方便等适用于行程短的场合。缺点是行程短一般不超过mm。平膜片的行程更短约为其直径的。()磁性开关气缸磁性开关气缸是指在气缸的活塞上安装有磁环在缸筒上直接安装磁性开关磁性开关用来检测气缸行程的位置控制气缸往复运动。因此就不需要在缸筒上安装行程阀或行程开关来检测气缸活塞位置也不需要在活塞杆上设置挡块。其工作原理如图,所示。它是在气缸活塞上安装永久磁环在缸筒外壳上装有舌簧开关。开关内装有舌簧片、保护电路和动作指示灯等均用树脂塑封在一个盒子内。当装有永久磁铁的活塞运动到舌簧片附近磁力线通过舌簧片使其磁化两个簧片被吸引接触则开关接通。当永久磁铁返回离开时磁场减弱两簧片弹开则开关断开。由于开关的接通或断开使电磁阀换向从而实现气缸的往复运动。andduediligenceevaluationsarticlendheadoffice,branch(jurisdiction),riskmanagement,marketingmanagementbranchwithintheDepartment'screditbusinesspersonassumedresponsibilityforthesupervisionandinspectionandduediligenceevaluationsArticlerd,HeadOffice,branches(jurisdiction),riskmanagement,MarketingManagementDepartmentthroughonsiteandoffsiteinspection,investigationreport,interviewswithinvestigatorsforpreloaninvestigationworkbywayofconductingsupervisionandinspection,qualityevaluationpreloaninvestigationwork,andbasedontheevaluationresults,theimplementationofdiversitymanagementththecontrolandinspection(a)theimplementationofthecreditsystem:thereisnobreachofcreditpolicyrelatingtothegrantingofcreditandtheheadoffice(B)dualcreditrating:timelinessofratings,whethertheprovisionsoftherating,ratingresultsareaccurate(C)thesurveycontents:datacollectioniscomplete,reportwritingiscomprehensive,indicatorsanalysisisobjective,real,conclusionsandthefactsareconsistentandreasonable(D)doubleimplementationofinvestigationssystem:practicalimplementationofdoublesystem(E)othersupervisionandinspectionofthecontentsthduediligenceevaluationofficesandbranches(jurisdiction),riskmanagement,MarketingManagementDepartmentagreedtocarryoutpreloaninvestigationsupervisionandinspectionwork,evaluatewhetherinvestigatorsduediligencetodeterminewhethertheexemptionshouldbeInvestigatorsshouldbecompatiblewithDuediligenceassessmentshouldbebasedonthefactthat,followingtheprinciplesofobjectivity,impartialityandfairnessArticlethhead图,磁性开关气缸,动作指示灯,保护电路,开关外壳,导线,活塞,磁环,缸筒,舌簧开关气缸磁性开关与其它开关的比较见表。表错误~未定义书签。气缸磁性开关与其它开关的比较开关形式控制原理成本调整安装复杂性()带阀气缸带阀气缸是由气缸、磁性开关磁场变化低方便不占位置换向阀和速度控制阀等组成的一种组行程开关机械触点低麻烦占位置合式气动执行元件。它省去了连接管道接近开关阻抗变化高麻烦占位置和管接头减少了能量损耗具有结构紧凑安装方便等优点。带阀气缸的阀有光电开关光的变化高麻烦占位置电控、气控、机控和手控等各种控制方式。阀的安装形式有安装在气缸尾部、上部等几种。如图,所示电磁换向阀安装在气缸的上部当有电信号时则电磁阀被切换输出气压可直接控制气缸动作。图,带阀组合气缸,管接头,气缸,气管,电磁换向阀,换向阀底板,单向节流阀组合件,密封圈。图,为带导杆气缸在缸筒两侧配导向用的滑动轴承(轴()带导杆气缸瓦式或滚珠式)因此导向精度高承受横向载荷能力强。andduediligenceevaluationsarticlendheadoffice,branch(jurisdiction),riskmanagement,marketingmanagementbranchwithintheDepartment'screditbusinesspersonassumedresponsibilityforthesupervisionandinspectionandduediligenceevaluationsArticlerd,HeadOffice,branches(jurisdiction),riskmanagement,MarketingManagementDepartmentthroughonsiteandoffsiteinspection,investigationreport,interviewswithinvestigatorsforpreloaninvestigationworkbywayofconductingsupervisionandinspection,qualityevaluationpreloaninvestigationwork,andbasedontheevaluationresults,theimplementationofdiversitymanagementththecontrolandinspection(a)theimplementationofthecreditsystem:thereisnobreachofcreditpolicyrelatingtothegrantingofcreditandtheheadoffice(B)dualcreditrating:timelinessofratings,whethertheprovisionsoftherating,ratingresultsareaccurate(C)thesurveycontents:datacollectioniscomplete,reportwritingiscomprehensive,indicatorsanalysisisobjective,real,conclusionsandthefactsareconsistentandreasonable(D)doubleimplementationofinvestigationssystem:practicalimplementationofdoublesystem(E)othersupervisionandinspectionofthecontentsthduediligenceevaluationofficesandbranches(jurisdiction),riskmanagement,MarketingManagementDepartmentagreedtocarryoutpreloaninvestigationsupervisionandinspectionwork,evaluatewhetherinvestigatorsduediligencetodeterminewhethertheexemptionshouldbeInvestigatorsshouldbecompatiblewithDuediligenceassessmentshouldbebasedonthefactthat,followingtheprinciplesofobjectivity,impartialityandfairnessArticlethhead,典型带导杆气缸的结构,典型带导杆气缸的结构()无杆气缸无杆气缸是指利用活塞直接或间接方式连接外界执行机构并使其跟随活塞实现往复运动的气缸。这种气缸的最大优点是节省安装空间。)磁性无杆气缸活塞通过磁力带动缸体外部的移动体做同步移动其结构如图,所示。它的工作原理是:在活塞上安装一组高强磁性的永久磁环磁力线通过薄壁缸筒与套在外面的另一组磁环作用由于两组磁环磁性相反具有很强的吸力。当活塞在缸筒内被气压推动时则在磁力作用下带动缸筒外的磁环套一起移动。气缸活塞的推力必须与磁环的吸力相适应。图,磁性无杆气缸,套筒,外磁环,外磁导板,内磁环,内磁导板,压盖,卡环,活塞,活塞轴,缓冲柱塞,气缸筒,端盖,进、排气口:机械接触式无杆气缸称机械接触式无杆气缸其结构如,所示。在气缸缸管轴向开有一条槽活塞与滑块在槽上部移动。为了防止泄漏及防尘需要在开口部采用聚氨脂密封带和防尘不锈钢带固定在两端缸盖上活塞架穿过槽把活塞与滑块连成一体。活塞与滑块连接在一起带动固定在滑块上的执行机构实现往复运动。这种气缸的特点是:)与普通气缸相比在同样行程下可缩小安装位置)不需设置防转机构)适用于缸径,mm最大行程在缸径mm时可达m)速度高标准型可达,ms高速型可达到,ms。andduediligenceevaluationsarticlendheadoffice,branch(jurisdiction),riskmanagement,marketingmanagementbranchwithintheDepartment'screditbusinesspersonassumedresponsibilityforthesupervisionandinspectionandduediligenceevaluationsArticlerd,HeadOffice,branches(jurisdiction),riskmanagement,MarketingManagementDepartmentthroughonsiteandoffsiteinspection,investigationreport,interviewswithinvestigatorsforpreloaninvestigationworkbywayofconductingsupervisionandinspection,qualityevaluationpreloaninvestigationwork,andbasedontheevaluationresults,theimplementationofdiversitymanagementththecontrolandinspection(a)theimplementationofthecreditsystem:thereisnobreachofcreditpolicyrelatingtothegrantingofcreditandtheheadoffice(B)dualcreditrating:timelinessofratings,whethertheprovisionsoftherating,ratingresultsareaccurate(C)thesurveycontents:datacollectioniscomplete,reportwritingiscomprehensive,indicatorsanalysisisobjective,real,conclusionsandthefactsareconsistentandreasonable(D)doubleimplementationofinvestigationssystem:practicalimplementationofdoublesystem(E)othersupervisionandinspectionofthecontentsthduediligenceevaluationofficesandbranches(jurisdiction),riskmanagement,MarketingManagementDepartmentagreedtocarryoutpreloaninvestigationsupervisionandinspectionwork,evaluatewhetherinvestigatorsduediligencetodeterminewhethertheexemptionshouldbeInvestigatorsshouldbecompatiblewithDuediligenceassessmentshouldbebasedonthefactthat,followingtheprinciplesofobjectivity,impartialityandfairnessArticlethhead其缺点是:)密封性能差容易产生外泄漏。在使用三位阀时必须选用中压式)受负载力小为了增加负载能力必须增加导向机构。图,机械接触式无杆气缸l,节流阀,缓冲柱塞,密封带,防尘不锈钢带,活塞,滑块,活塞架图,机械接触式无杆气缸()锁紧气缸带有锁紧装置的气缸称为锁紧气缸。按锁紧位置分为行程末端l,节流阀,缓冲柱塞,密封带锁紧型和任意位置锁紧型。,防尘不锈钢带,活塞,滑块,活塞架)行程末端锁紧型气缸如图,所示当活塞运动到行程末端气压释放后锁定活塞在弹簧力的作用下插入活塞杆的卡槽中活塞杆被锁定。供气加压时锁定活塞缩回退出卡槽而开锁活塞杆便可运动。图,带端锁气缸的结构原理a)手动解除非锁式b)手动解除锁式。,锁定活塞,橡胶帽,帽,缓冲垫圈,锁用弹簧,密封件,导向套,螺钉,旋钮,弹簧,限位环)任意位置锁紧型气缸按锁紧方式可分为卡套锥面式、弹簧式和偏心式等多种形式。卡套锥面式锁紧装置由锥形制动活塞、制动瓦、制动臂和制动弹簧等构成其结构原理如图,所示。作用在锥状锁紧活塞上的弹簧力由于楔的作用而被放大再由杠杆原理得到放大。这个放大的作用力作用在制动瓦上把活塞杆锁紧。要释放对活塞的锁紧向供气口A′供应压缩空气把锁紧弹簧力撤掉。andduediligenceevaluationsarticlendheadoffice,branch(jurisdiction),riskmanagement,marketingmanagementbranchwithintheDepartment'screditbusinesspersonassumedresponsibilityforthesupervisionandinspectionandduediligenceevaluationsArticlerd,HeadOffice,branches(jurisdiction),riskmanagement,MarketingManagementDepartmentthroughonsiteandoffsiteinspection,investigationreport,interviewswithinvestigatorsforpreloaninvestigationworkbywayofconductingsupervisionandinspection,qualityevaluationpreloaninvestigationwork,andbasedontheevaluationresults,theimplementationofdiversitymanagementththecontrolandinspection(a)theimplementationofthecreditsystem:thereisnobreachofcreditpolicyrelatingtothegrantingofcreditandtheheadoffice(B)dualcreditrating:timelinessofratings,whethertheprovisionsoftherating,ratingresultsareaccurate(C)thesurveycontents:datacollectioniscomplete,reportwritingiscomprehensive,indicatorsanalysisisobjective,real,conclusionsandthefactsareconsistentandreasonable(D)doubleimplementationofinvestigationssystem:practicalimplementationofdoublesystem(E)othersupervisionandinspectionofthecontentsthduediligenceevaluationofficesandbranches(jurisdiction),riskmanagement,MarketingManagementDepartmentagreedtocarryoutpreloaninvestigationsupervisionandinspectionwork,evaluatewhetherinvestigatorsduediligencetodeterminewhethertheexemptionshouldbeInvestigatorsshouldbecompatiblewithDuediligenceassessmentshouldbebasedonthefactthat,followingtheprinciplesofobjectivity,impartialityandfairnessArticlethhead图,制动气缸制动装置工作原理图,制动气缸制动装置工作原理a)自由状态b)锁紧状态l,制动瓦,制动瓦座,转轴,制动臂,压轮,锥形制动活塞,制动弹簧()气动手爪气动手爪这种执行元件是一种变型气缸。它可以用来抓取物体实现机械手各种动作。在自动化系统中气动手爪常应用在搬运、传送工件机构中抓取、拾放物体。图,图,平行开合手指平行开合手指气动手爪有平行开合手指(如图,所示)、肘节摆动开合手爪、有两爪、三爪和四爪等类型其中两爪中有平开式和支点开闭式驱动方式有直线式和旋转式。气动手爪的开闭一般是通过由气缸活塞产生的往复直线运动带动与手爪相连的曲柄连杆、滚轮或齿轮等机构驱动各个手爪同步做开、闭运动。()气液阻尼缸气缸以可压缩空气为工作介质动作快但速度稳定性差当负载变化较大时容易产生“爬行”或“自走”现象。另外压缩空气的压力较低因而气缸的输出力较小。为此经常采用气缸和油缸相结合的方式组成各种气液组合式执行元件以达到控制速度或增大输出力的目的。气液阻尼缸是利用气缸驱动油缸油缸除起阻尼作用外还能增加气缸的刚性(因为油是不可压缩的)发挥了液压传动稳定、传动速度较均匀的优点。常用于机床和切削装置的进给驱动装置。串联式气液阻尼缸的结构如图,所示。它采用一根活塞杆将两活塞串在一起油缸和气缸之间用隔板隔开防止气体串入油缸中。当气缸左端进气时气缸将克服负载阻力带动油缸向右运动调节节流阀开度就能改变阻尼缸活塞的运动速度。andduediligenceevaluationsarticlendheadoffice,branch(jurisdiction),riskmanagement,marketingmanagementbranchwithintheDepartment'screditbusinesspersonassumedresponsibilityforthesupervisionandinspectionandduediligenceevaluationsArticlerd,HeadOffice,branches(jurisdiction),riskmanagement,MarketingManagementDepartmentthroughonsiteandoffsiteinspection,investigationreport,interviewswithinvestigatorsforpreloaninvestigationworkbywayofconductingsupervisionandinspection,qualityevaluationpreloaninvestigationwork,andbasedontheevaluationresults,theimplementationofdiversitymanagementththecontrolandinspection(a)theimplementationofthecreditsystem:thereisnobreachofcreditpolicyrelatingtothegrantingofcreditandtheheadoffice(B)dualcreditrating:timelinessofratings,whethertheprovisionsoftherating,ratingresultsareaccurate(C)thesurveycontents:datacollectioniscomplete,reportwritingiscomprehensive,indicatorsanalysisisobjective,real,conclusionsandthefactsareconsistentandreasonable(D)doubleimplementationofinvestigationssystem:practicalimplementationofdoublesystem(E)othersupervisionandinspectionofthecontentsthduediligenceevaluationofficesandbranches(jurisdiction),riskmanagement,MarketingManagementDepartmentagreedtocarryoutpreloaninvestigationsupervisionandinspectionwork,evaluatewhetherinvestigatorsduediligencetodeterminewhethertheexemptionshouldbeInvestigatorsshouldbecompatiblewithDuediligenceassessmentshouldbebasedonthefactthat,followingtheprinciplesofobjectivity,impartialityandfairnessArticlethhead图,气液阻尼缸图,气液阻尼缸()摆动气缸摆动气缸是一种在小于角度范围内做往复摆动的气缸它是将压缩空气的压力能转换成机械能输出力矩使机构实现往复摆动。摆动气缸按结构特点可分为叶片式和活塞式两种。)叶片式摆动气缸单叶片式摆动气缸的结构原理如图,所示。它是由叶片轴转子(即输出轴)、定子、缸体和前后端盖等部分组成。定子和缸体固定在一起叶片和转子联在一起。在定子上有两条气路当左路进气时右路排气压缩空气推动叶片带动转子顺时针摆动。反之作逆时针摆动。叶片式摆动气缸体积小重量最轻但制造精度要求高密封困难泄漏是较大而且动密封接触面积大密封件的摩擦阻力损失较大输出效率较低小于。因此在应用上受到限制一般只用在安装位置受到限制的场合如夹具的回转阀门开闭及工作台转位等。图,单叶片式摆动气缸工作原理图图,单叶片式摆动气缸,叶片,转子,定子,缸体工作原理图,叶片,转子,定子,缸体)活塞式摆动气缸活塞式摆动气缸是将活塞的往复运动通过机构转变为输出轴的摆动运动。按结构不同可分为齿轮齿条式、螺杆式和曲柄式等几种。andduediligenceevaluationsarticlendheadoffice,branch(jurisdiction),riskmanagement,marketingmanagementbranchwithintheDepartment'screditbusinesspersonassumedresponsibilityforthesupervisionandinspectionandduediligenceevaluationsArticlerd,HeadOffice,branches(jurisdiction),riskmanagement,MarketingManagementDepartmentthroughonsiteandoffsiteinspection,investigationreport,interviewswithinvestigatorsforpreloaninvestigationworkbywayofconductingsupervisionandinspection,qualityevaluationpreloaninvestigationwork,andbasedontheevaluationresults,theimplementationofdiversitymanagementththecontrolandinspection(a)theimplementationofthecreditsystem:thereisnobreachofcreditpolicyrelatingtothegrantingofcreditandtheheadoffice(B)dualcreditrating:timelinessofratings,whethertheprovisionsoftherating,ratingresultsareaccurate(C)thesurveycontents:datacollectioniscomplete,reportwritingiscomprehensive,indicatorsanalysisisobjective,real,conclusionsandthefactsareconsistentandreasonable(D)doubleimplementationofinvestigationssystem:practicalimplementationofdoublesystem(E)othersupervisionandinspectionofthecontentsthduediligenceevaluationofficesandbranches(jurisdiction),riskmanagement,MarketingManagementDepartmentagreedtocarryoutpreloaninvestigationsupervisionandinspectionwork,evaluatewhetherinvestigatorsduediligencetodeterminewhethertheexemptionshouldbeInvestigatorsshouldbecompatiblewithDuediligenceassessmentshouldbebasedonthefactthat,followingtheprinciplesofobjectivity,impartialityandfairnessArticlethhead图,齿轮齿条式摆动气缸结构原理,齿条组件,弹簧柱销,滑块,端盖,缸体,轴承,轴,活塞,齿轮图,齿轮齿条式摆动气缸结构原理,齿条组件,弹簧柱销,滑块,端盖,缸体,轴承,轴,活塞,齿轮齿轮齿条式摆动气缸是通过连接在活塞上的齿条使齿轮回转的一种摆动气缸其结构原理如图,所示。活塞仅作往复直线运动摩擦损失少齿轮传动的效率较高此摆动气缸效率可达到左右。三、气缸的技术参数)气缸的输出力气缸理论输出力的设计计算与液压缸类似可参见液压缸的设计计算。如双作用单活塞杆气缸推力计算如下:理论推力(活塞杆伸出)F,Ap()t理论拉力(活塞杆缩回)F,Ap()t式中F、F气缸理论输出力(N)ttA、A无杆腔、有杆腔活塞面积(m)p气缸工作压力(Pa)。实际中由于活塞等运动部件的惯性力以及密封等部分的摩擦力活塞杆的实际输出力小于理论推力称这个推力为气缸的实际输出力。气缸的效率,是气缸的实际推力和理论推力的比值即F,,Ft()所以F,,Ap()andduediligenceevaluationsarticlendheadoffice,branch(jurisdiction),riskmanagement,marketingmanagementbranchwithintheDepartment'screditbusinesspersonassumedresponsibilityforthesupervisionandinspectionandduediligenceevaluationsArticlerd,HeadOffice,branches(jurisdiction),riskmanagement,MarketingManagementDepartmentthroughonsiteandoffsiteinspection,investigationreport,interviewswithinvestigatorsforpreloaninvestigationworkbywayofconductingsupervisionandinspection,qualityevaluationpreloaninvestigationwork,andbasedontheevaluationresults,theimplementationofdiversitymanagementththecontrolandinspection(a)theimplementationofthecreditsystem:thereisnobreachofcreditpolicyrelatingtothegrantingofcreditandtheheadoffice(B)dualcreditrating:timelinessofratings,whethertheprovisionsoftherating,ratingresultsareaccurate(C)thesurveycontents:datacollectioniscomplete,reportwritingiscomprehensive,indicatorsanalysisisobjective,real,conclusionsandthefactsareconsistentandreasonable(D)doubleimplementationofinvestigationssystem:practicalimplementationofdoublesystem(E)othersupervisionandinspectionofthecontentsthduediligenceevaluationofficesandbranches(jurisdiction),riskmanagement,MarketingManagementDepartmentagreedtocarryoutpreloaninvestigationsupervisionandinspectionwork,evaluatewhetherinvestigatorsduediligencetodeterminewhethertheexemptionshouldbeInvestigatorsshouldbecompatiblewithDuediligenceassessmentshouldbebasedonthefactthat,followingtheprinciplesofobjectivity,impartialityandfairnessArticlethhead气缸的效率取决于密封的种类气缸内表面和活塞杆加工的状态及润滑状态。此外气缸的运动速度、排气腔压力、外载荷状况及管道状态等都会对效率产生一定的影响。)负载率β从对气缸运行特性的研究可知要精确确定气缸的实际输出力是困难的。于是在研究气缸性能和确定气缸的出力时常用到负载率的概念。气缸的负载率β定义为气缸的实际负载F,,气缸的理论输出力Ft(l,)气缸的实际负载是由实际工况所决定的若确定了气缸负载率,则由定义就能确定气缸的理论输出力从而可以计算气缸的缸径。对于阻性负载如气缸用作气动夹具负载不产生惯性力一般选取负载率β为对于惯性负载如气缸用来推送工件负载将产生惯性力负载率β的取值如下β,当气缸低速运动v,mms时β,当气缸中速运动v,,mms时β,当气缸高速运动v,mms时。)气缸耗气量气缸的耗气量是活塞每分钟移动的容积称这个容积为压缩空气耗气量一般情况下气缸的耗气量是指自由空气耗气量。)气缸的特性气缸的特性分为静态特性和动态特性。气缸的静态特性是指与缸的输出力及耗气量密切相关的最低工作压力、最高工作压力、摩擦阻力等参数。气缸的动态特性是指在气缸运动过程中气缸两腔内空气压力温度活塞速度、位移等参数随时间的变化情况。它能真实地反映气缸的工作性能。四、气缸的选型及计算气缸的选型步骤气缸的选型应根据工作要求和条件正确选择气缸的类型。下面以单活塞杆双作用缸为例介绍气缸的选型步骤。()气缸缸径。根据气缸负载力的大小来确定气缸的输出力由此计算出气缸的缸径。()气缸的行程。气缸的行程与使用的场合和机构的行程有关但一般不选用满行程。()气缸的强度和稳定性计算()气缸的安装形式。气缸的安装形式根据安装位置和使用目的等因素决定。一般情况下采用固定式气缸。在需要随工作机构连续回转时(如车床、磨床等)应选用回转气缸。在活塞杆除直线运动外还需作圆弧摆动时则选用轴销式气缸。有特殊要求时应选用相应的特种气缸。()气缸的缓冲装置。根据活塞的速度决定是否应采用缓冲装置。()磁性开关。当气动系统采用电气控制方式时可选用带磁性开关的气缸。()其它要求。如气缸工作在有灰尘等恶劣环境下需在活塞杆伸出端安装防尘罩。要求无污染时需选用无给油或无油润滑气缸。气缸直径计算气缸直径的设计计算需根据其负载大小、运行速度和系统工作压力来决定。首先根据气缸安装及驱动负载的实际工况分析计算出气缸轴向实际负载F再由气缸平均运行速度来选定气缸的负载率,初步选定气缸工作压力(一般为MPa,MPa)再由F,,计算出气缸理论出力F最后计算出缸径及杆径并按标准圆整得到实际所需的缸径和杆径。t例题气缸推动工件在水平导轨上运动。已知工件等运动件质量为m,kg工件与导轨间的摩擦系数,,气缸行程s为mm经s时间工件运动到位系统工作压力p=MPa试选定气缸直径。解:气缸实际轴向负载F,mg,,N气缸平均速度sv,,,mmst选定负载率,,andduediligenceevaluationsarticlendheadoffice,branch(jurisdiction),riskmanagement,marketingmanagementbranchwithintheDepartment'screditbusinesspersonassumedresponsibilityforthesupervisionandinspectionandduediligenceevaluationsArticlerd,HeadOffice,branches(jurisdiction),riskmanagement,MarketingManagementDepartmentthroughonsiteandoffsiteinspection,investigationreport,interviewswithinvestigatorsforpreloaninvestigationworkbywayofconductingsupervisionandinspection,qualityevaluationpreloaninvestigationwork,andbasedontheevaluationresults,theimplementationofdiversitymanagementththecontrolandinspection(a)theimplementationofthecreditsystem:thereisnobreachofcreditpolicyrelatingtothegrantingofcreditandtheheadoffice(B)dualcreditrating:timelinessofratings,whethertheprovisionsoftherating,ratingresultsareaccurate(C)thesurveycontents:datacollectioniscomplete,reportwritingiscomprehensive,indicatorsanalysisisobjective,real,conclusionsandthefactsareconsistentandreasonable(D)doubleimplementationofinvestigationssystem:practicalimplementationofdoublesystem(E)othersupervisionandinspectionofthecontentsthduediligenceevaluationofficesandbranches(jurisdiction),riskmanagement,MarketingManagementDepartmentagreedtocarryoutpreloaninvestigationsupervisionandinspectionwork,evaluatewhetherinvestigatorsduediligencetodeterminewhethertheexemptionshouldbeInvestigatorsshouldbecompatiblewithDuediligenceassessmentshouldbebasedonthefactthat,followingtheprinciplesofobjectivity,impartialityandfairnessArticlethhead则气缸理论输出力F,,,NF,双作用气缸理论推力F,,D,pFtD,,,mm,p气缸直径按标准选定气缸缸径为mm。andduediligenceevaluationsarticlendheadoffice,branch(jurisdiction),riskmanagement,marketingmanagementbranchwithintheDepartment'screditbusinesspersonassumedresponsibilityforthesupervisionandinspectionandduediligenceevaluationsArticlerd,HeadOffice,branches(jurisdiction),riskmanagement,MarketingManagementDepartmentthroughonsiteandoffsiteinspection,investigationreport,interviewswithinvestigatorsforpreloaninvestigationworkbywayofconductingsupervisionandinspection,qualityevaluationpreloaninvestigationwork,andbasedontheevaluationresults,theimplementationofdiversitymanagementththecontrolandinspection(a)theimplementationofthecreditsystem:thereisnobreachofcreditpolicyrelatingtothegrantingofcreditandtheheadoffice(B)dualcreditrating:timelinessofratings,whethertheprovisionsoftherating,ratingresultsareaccurate(C)thesurveycontents:datacollectioniscomplete,reportwritingiscomprehensive,indicatorsanalysisisobjective,real,conclusionsandthefactsareconsistentandreasonable(D)doubleimplementationofinvestigationssystem:practicalimplementationofdoublesystem(E)othersupervisionandinspectionofthecontentsthduediligenceevaluationofficesandbranches(jurisdiction),riskmanagement,MarketingManagementDepartmentagreedtocarryoutpreloaninvestigationsupervisionandinspectionwork,evaluatewhetherinvestigatorsduediligencetodeterminewhethertheexemptionshouldbeInvestigatorsshouldbecompatiblewithDuediligenceassessmentshouldbebasedonthefactthat,followingtheprinciplesofobjectivity,impartialityandfairnessArticlethhea
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