欢迎来到天天文库
浏览记录
ID:58681874
大小:4.78 MB
页数:61页
时间:2020-10-05
《第五章 方向控制阀-----液压控制ppt课件.ppt》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、Chp.5HydraulicControlValves液压控制阀5.1Introduction概述5.2DirectionalControlValves方向阀5.3PressureOperatedValves压力阀5.4FlowControlValves流量阀5.5SomeSpecialValves其它阀5.1Introduction概述1Functions作用Tocontrolthedirectionofoilflow(DirectionConterolValves)、theoilpressure(PressureConterolValve
2、s)andtheflowrate(FlowConterolValves)inahydraulicsystem。控制液压系统的油液流动方向、压力和流量。Instructure:consistsofavalvebody、avalvecore(spool、coneorball,showninFig.5-1)andtheoperationelements。结构上都包含有阀体、阀芯和阀芯操作机构。2Basiccharacteristics基本特征Inoperatingprinciple:theorificeflowformulashouldbekept
3、true。符合孔口流量公式(阀的开口度、进出口压差及流量间的关系)。3Classifications(infunctions)类型(按功能分)HydraulicControlValves液压控制阀DirectionControlValves方向阀DirectionSwitchValves换向阀CheckValves单向阀PressureControlValves压力阀ReliefValves溢流阀PressureReduceValves减压阀SequenceValves顺序阀PressureSwitches压力继电器FlowControlVa
4、lves流量阀ThrottleValves节流阀FlowDividerValve分流阀Speed-regulatingValve调速阀Tab.5-1Relief-throttleValve溢流节流阀5.2Directionalcontrolvalves方向控制阀方向控制阀:用于控制液压系统中油液的流动方向和液流通路的启闭,从而控制执行元件的运动方向、启动与停止等功能的液压阀。按用途,可分为单向阀(CheckValves)和换向阀(DirectionSwitchValves)两大类。TherearetwotypesofCheckvalves:I
5、n-lineCheckvalveandPilot-operatedCheckvalve。有普通单向阀(简称单向阀)和液控单向阀两种。In-lineCheckvalve普通单向阀Functions作用Acheckvalveallowsflowinonedirection,butblocksflowinthereversedirection。使液流只能向一个方向流过而反向截止。1Checkvalves单向阀Structure结构Fig.5-2Valvebody阀体1Valvecore阀芯2(有钢球式和锥阀式两种)Spring弹簧3Operatin
6、gprinciple工作原理Flowthroughtheinletporttotheoutletport:Overcomingtheslightforceofspring;正向流动:仅克服弹簧力(及摩擦力);Ifflowdirectionreverses:Pressuredoilandthespringpushvalvecoreagainsttheseat,flowcannotpassthrough。反向流动:液压力及弹簧力方向一致,无法打开阀口。一般阀内弹簧较软,开启压力约0.3~0.5bar。若作背压阀用,弹簧设计较硬,开启压力约2~6b
7、ar,使系统回油保持一定背压。Hydraulicoperatedcheckvalve液控单向阀Functions作用Permitsfreeflowinonedirection,andpermitsflowinthenormallyblockedoppositeonlyifpolitpressureisappliedatthepilotportpc。单方向流动,若给控制信号时可反向导通。Structure结构Fig.5-3In-lineCheckvalve+Pilot-controlled在普通单向阀上增加液控部分。Fig.5-3Graphic
8、symbolsa:In-lineCheckvalveb:HydraulicoperatedcheckvalveApplication应用双向液压锁2Directio
此文档下载收益归作者所有