比例阀基本原理.pptx

1、比例溢流阀原理讲解设备部热控四班：冯春雨 2011.111) 一般认为一个简单的液压系统由油箱（A）、电动机（B）、泵（C）、溢流阀（D）、过滤器（E）、流量控制阀（F）、方向控制阀（G）、和油缸（H）组成。2) 油缸的运动是由流量控制阀（确定运动的速度）和方向控制阀（油缸运动的方向）控制。ABCDEFHG当电磁阀得电时，油缸活塞将伸出和回缩,其速度由流量控制阀确定，而电磁阀不具有控制速度的能力。BASIC SYSTEMA three position solenoid valve can:- extend伸出 the cylinder气缸- retract缩回 the cylinder- s

2、top the cylinder因此电磁阀的动作非常象一个电路中的开关在此位置灯是关闭状态. 在另外一个位置是开启状态，而没有中间状态。and in the other position it is switched on but there are no intermediate states.然而众所周知，另一种形式的开关能够用来控制灯泡，调光开关However, another type of switch can be used for controlling a light bulb known as a dimmer switch.在这个例子中，这个开关能够被转到全开和全关的任一位

3、置，来调整灯泡的亮度In this case, the switch can be turned to any position between fully off and fully on to vary the brightness of the bulb.In this case, the switch can be turned to any position between fully off and fully on to vary the brightness of the bulb.In this case, the switch can be turned to any po

4、sition between fully off and fully on to vary the brightness of the bulb.In this case, the switch can be turned to any position between fully off and fully on to vary the brightness of the bulb.In this case, the switch can be turned to any position between fully off and fully on to vary the brightne

5、ss of the bulb.In this case, the switch can be turned to any position between fully off and fully on to vary the brightness of the bulb.在这个例子中，这个开关能够被转到全开和全关的任一位置，来调整灯泡的亮度。In this case, the switch can be turned to any position between fully off and fully on to vary the brightness of the bulb.In this

6、 case, the switch can be turned to any position between fully off and fully on to vary the brightness of the bulb.2) 阀芯能够移动到在任一位置，而不仅仅是三个不连续的位置。阀芯在离开中位的方向仍然确定油缸运动的方向，但阀芯离开中位的距离控制活塞的速度。1) 比例方向阀能够被看作与调光开关具有同样功能。A proportional directional valve can be thought of as the dimmer switch equivalent of an el

7、ectrical switch.BASIC SYSTEM于是在实际上比例阀可以同时作为方向阀和流量阀来使用。So in effect the proportional directional valve is acting as both a directional valve and a flow control valve.SWITCHING SOLENOID VALVE一个传统的电磁阀能够被认为是一个简单的开关阀。A conventional solenoid valve can be thought of as a simple switching valve.它可以被一些只有简单电流

8、通断的开关的电设备来控制It is controlled by some form of electrical device which simply switches the electrical current on or off.SWITCHING SOLENOID VALVEA conventional solenoid valve can be thought of as a simple switching valve.It is controlled by some form of electrical device which simply switches the elect

9、rical current on or off.SWITCHING SOLENOID VALVEA conventional solenoid valve can be thought of as a simple switching valve.It is controlled by some form of electrical device which simply switches the electrical current on or off.PROPORTIONAL VALVE一个比例方向阀是由与一个与调光开关非常象的电设备控制的。A proportional direction

10、al valve however will be controlled by an electrical device more like a dimmer switch.PROPORTIONAL VALVE通过改变两个之一电磁铁的电流，阀芯移动的位移能够被改变，因此控制了通过阀的流量。By varying the current to either solenoid, the amount of spool movement can be varied and hence the amount of flow through the valve can be controlled.PROPO

11、RTIONAL VALVEBy varying the current to either solenoid, the amount of spool movement can be varied and hence the amount of flow through the valve can be controlled.PROPORTIONAL VALVEBy varying the current to either solenoid, the amount of spool movement can be varied and hence the amount of flow thr

12、ough the valve can be controlled.PROPORTIONAL VALVEBy varying the current to either solenoid, the amount of spool movement can be varied and hence the amount of flow through the valve can be controlled.PROPORTIONAL VALVEBy varying the current to either solenoid, the amount of spool movement can be v

13、aried and hence the amount of flow through the valve can be controlled.PROPORTIONAL VALVEBy varying the current to either solenoid, the amount of spool movement can be varied and hence the amount of flow through the valve can be controlled.PROPORTIONAL SOLENOID因此不像传统的电磁阀，通过比例阀线圈的电流需要被调整，而不仅仅是开关式的通断。

14、比例阀电磁铁的结构与开关式电磁铁是相似的。电磁铁包括:- 线圈 (A)- 框架 (B)- 电枢 (C)- 电极片 (D)- 顶针 (E)电枢被 包在一个芯轴管（F）中。 (同时全部的总成经常被压进一个树脂塑料的外罩（G）中）ABCDFGEPROPORTIONAL SOLENOIDWhen a voltage is applied作用于 to the coil线圈 connections, an electrical current will flow through the coil.PROPORTIONAL SOLENOID1) 接下来，电流生成一个磁场，磁场主要集中在金属框架、电机片和电枢

15、中In turn, the electrical current creates a magnetic field which is concentrated in the metal frame, pole piece and armature.2) 然而在磁回路的电机片和电枢之间有一个间隙，于是产生一个力，其作用是关闭这个间隙以完成这个磁回路。There is however a gap in the magnetic circuit between the pole piece and armature so a force is created which acts to close

16、this gap and complete the magnetic circuit.PROPORTIONAL SOLENOID1)顶针连接着电磁铁和阀芯，通常移动阀芯压缩弹簧。 The push-pin connects the solenoid to the valve spool and normally moves the spool against a spring.2) 电磁铁产生的力The 大小由磁场强度决定，磁场强度与通过线圈的电流成比例force created by the solenoid is determined by the strength of the magn

17、etic field which itself is proportional to the current flowing through the coil.PROPORTIONAL SOLENOID增大线圈电流将加大电磁的力，因此推动阀芯压缩弹簧产生一个更大的位移。Increasing the coil current will increase the solenoid force and hence move the spool a greater amount against the spring.PROPORTIONAL SOLENOIDIncreasing the coil cu

18、rrent will increase the solenoid force and hence move the spool a greater amount against the spring.PROPORTIONAL SOLENOIDIncreasing the coil current will increase the solenoid force and hence move the spool a greater amount against the spring.FIFIPROPORTIONAL SOLENOID电磁铁被设计成电磁力(F)与线圈电流(I)成线性比例关系。这意味

19、着电磁力仅与线圈电流有关。开关电磁阀阀芯比例阀与开关电磁阀之间的另一个区别是阀芯的设计。A further difference between a switching solenoid valve and a proportional valve is in the design of the spool. SSQQSWITCHING SOLENOID SPOOL1) 对于开关阀，阀芯被设计为当阀得电时，将压降最小化。2)这意味着，控制小流量 阀开口要求非常小并且很困难。Which would mean that to control low flow rates, the amount o

20、f spool opening required would be very small and difficult to control.SSQPROPORTIONAL SPOOL1) 比例阀阀芯具有比较宽的边缘带有槽口的台肩。A proportional valve spool therefore has wider lands直线刀面部 with notches cut into the edges.SSQPROPORTIONAL SPOOL2) 因此尽管通过阀的最大流量被减少了（与开关阀对照）但小流量特别容易控制，阀的开口更有规则。So although the maximum flo

21、w through the valve may be reduced (compared to a switching valve) low flows in particular are more easily controlled and the opening of the valve is more gradual.1) 比例阀阀芯具有比较宽的边缘带有槽口的台肩。SSQPROPORTIONAL SPOOL依据控制的最大流量，不同的阀芯能被适用于不同形状、大小或阀芯槽口的大小特定的阀Depending upon the maximum flow to be controlled, dif

22、ferent spools can be fitted to a particular valve which have different shape, size or number of spool notches.直动式比例溢流阀1)比例阀也可以被用来控制压力。在此比例电磁铁被用来推动一个锥阀芯通过一个弹簧压缩阀座。电磁力越大，推开锥阀芯离开阀座打开阀的压力要求越大。Proportional valves can also be used to control pressure. In this case a proportional solenoid is used to push a

23、 poppet against a seat via a spring. The greater the solenoid force the greater the pressure required to push the poppet off its seat and open the valve.DIRECT ACTING PROPORTIONAL RELIEF VALVE2) 这里提供一个直动式溢流阀功能，但象多数此类阀一样，只能允许一个小流量通过该阀。This provides a direct acting relief valve function but like most

24、such valves, it is only possible to pass small flow rates through the valve.1)比例阀也可以被用来控制压力。在此比例电磁铁被用来推动一个锥阀芯通过一个弹簧压缩阀座。电磁力越大，推开锥阀芯离开阀座打开阀的压力要求越大。Proportional valves can also be used to control pressure. In this case a proportional solenoid is used to push a poppet against a seat via a spring. The g

25、reater the solenoid force the greater the pressure required to push the poppet off its seat and open the valve.两-级比例溢流阀为控制大流量，直动式比例溢流阀能被用来作为一个两级溢流阀（或减压阀）的先导级To control higher flow rates, the proportional direct acting relief valve can be used as the pilot stage of a two-stage relief (or reducing val

26、ve).TWO-STAGE PROPORTIONAL RELIEF VALVETo control higher flow rates, the proportional direct acting relief valve can be used as the pilot stage of a two-stage relief (or reducing valve).BENEFITS OF PROPORTIONAL SYSTEMS比例系统的优点远程控制 传统系统在常规系统中为了调整执行器的速度，流量控制阀必须安装在一个方便的或便于接近的位置，这意味着与操纵台连接的液压管路经常运行在高压下。远

27、程控制 比例系统对于比例系统，控制阀为电子调节，仅需要低功率的电缆连接操纵台和比例阀即可。With a proportional system however, where control valve adjustment is electronic, only low-power electrical cables need to be connected between the operators desk and the valve.PLC 远程控制 比例系统今天更多的是，机械控制被数字电子控制所取代，这里情况也是一样，比例阀的电子控制能力为液压系统和电子控制器之间提供一个简单的接口。比

28、例压力控制使用比例方向和压力控制阀意味着机器的所有液压功能（运动和力）能被电子地控制。电磁阀的反应时间 SOLENOID VALVE RESPONSE TIMEA further benefit of proportional valves is the ability to electronically control the speed of operation of the valve.比例阀地进一步功能是电子控制阀操作速度的能力。0.015SSOLENOID VALVE RESPONSE TIMEDepending upon its size and voltage supply, a

29、 conventional switching solenoid valve will have an energisation response time of approximately 15 milli-seconds. 依据阀的大小和提供的电压，一个传统的开关电磁阀对于一个得电动作的反应时间是15毫秒。0.040SSOLENOID VALVE RESPONSE TIMEThe de-energisation response time will be only slightly slower (typically around 25 ms) since the return sprin

30、g produces less force than the solenoid . 由于回程弹簧的力小于电磁铁，断电的反应时间稍慢（通常25ms左右），S比例阀的反应时间 PROPORTIONAL VALVE RESPONSE TIME比例阀阀芯的运动速度能被阀电磁铁的供给电子信号确定。通过逐渐地增加或降低信号（叫做斜坡）可以完成几秒的得电和断电时间。The speed ofmovement of a proportional valve spool however can be determined by the electronic signal fed to the valve sole

31、noid. By gradually increasing or decreasing the the signal (known as ramping), it is possible to achieve energisation and de-energisation response times of several seconds.1.000SPROPORTIONAL VALVE RESPONSE TIME比例阀阀芯的运动速度能被阀电磁铁的供给电子信号确定。通过逐渐地增加或降低信号（叫做斜坡）可以完成几秒的得电和断电时间。2.000 SPROPORTIONAL VALVE RESPO

32、NSE TIME比例阀阀芯的运动速度能被阀电磁铁的供给电子信号确定。通过逐渐地增加或降低信号（叫做斜坡）可以完成几秒的得电和断电时间。3.000SPROPORTIONAL VALVE RESPONSE TIME比例阀阀芯的运动速度能被阀电磁铁的供给电子信号确定。通过逐渐地增加或降低信号（叫做斜坡）可以完成几秒的得电和断电时间。顶升举例-传统系统 LIFT EXAMPLE - CONVENTIONAL SYSTEM为什么控制阀的阀芯运动速度是用用处的原因是减少系统中的震动，这可以通过控制执行器的加速和减速来完成。假设举例，一个简单的液压系统被用于宾馆中的乘客电梯操作，比较容易说明。顶升举例-传统

33、系统 LIFT EXAMPLE - CONVENTIONAL SYSTEM.当这磁阀得电降低电梯时，阀芯将快速运动，这意味着油缸将极快地加速到其最大速度（最大速度由控制阀F的设置确定），这个突然的启动会给电梯乘客一个极不舒服的感受。F顶升举例-传统系统 LIFT EXAMPLE - CONVENTIONAL SYSTEM同样地,当电梯达到终点时，电磁阀将非常快地关闭产生一个突然地 停止，当然又是一个极不舒服地动作。在一个真正地液压系统中，由于执行器突然起停而产生地震动会产生一个高的尖峰压力，从原理上来说这将导致液压泄漏。顶升举例- 比例系统PROPORTIONAL SYSTEM如果电磁阀和流量

34、控制阀被一个比例阀取代，不仅电梯的速度可以被电子地调整，而且电梯的起停也可以被控制。顶升举例- 比例系统LIFT EXAMPLE - PROPORTIONAL SYSTEM比例阀能够足够慢地打开以提供一个平滑加速度使电梯达到最大速度。The proportional valve can be opened sufficiently slowly to provide a smooth acceleration of the lift up to its maximum speed. 顶升举例- 比例系统LIFT EXAMPLE - PROPORTIONAL SYSTEM同样地，减加速度也能够被

35、控制，使阀芯运动回中位的速度变慢。And likewise the deceleration can be controlled by slowing down the speed of spool movement back to the centre condition. timeDistance运动控制 MOTION CONTROL因此总的来说，比例阀能够提供全部的运动控制包括：In general therefore, proportional valves are capable of providing full motion control in terms of:timeAcc

36、elerationDistanceMOTION CONTROL1. A smooth and controlled acceleration of an actuator up to its maximum speed.一个平滑和受控的加速度，使执行器达到最大速度。timeAccelerationVelocityDistanceMOTION CONTROL2. Control of the actuator velocity and if necessary maintaining it constant with varying loads.执行器速度的控制，如果必要维持其在变化负载下的稳定

37、。timeAccelerationDecelerationVelocityDistanceMOTION CONTROL3. A smooth deceleration with minimal pressure peaks.一个平滑的带有最小化压力峰值的减加速度timePositionAccelerationDecelerationVelocityDistanceMOTION CONTROL4. By using suitable sensing devices, the proportional valve can also be used to control the actuator s

38、topping position to high levels of accuracy.通过使用合适的传感装置，比例阀也可以被用来高精度地控制执行器的位置timeForce力控制 FORCE CONTROL比例阀也能够被用来控制执行器力地输出，通过控制应用于执行器上地压强。（例如在压机中或注塑机应用）Proportional valves can also be used to control the force output from an actuator (for example in press or plastic injection moulding applications) b

39、y controlling the pressure applied to the actuator.timeForceFORCE CONTROL在这样的实例中，不仅要求控制最大的执行器压力。而且要求控制应用中或运动中的压力等级。In such cases it is often necessary to control not only the maximum actuator pressure but also the rate at which the pressure is applied or removed.timeForceFORCE CONTROLIn fact the mac

40、hine cycle may consist of a series of ramps and holding periods all of which can be achieved with just the one proportional valve.实际上机器工作周期可能由一系列的斜坡和停止阶段组成，所有这些可以由一个比例阀来完成。timeForceFORCE CONTROLAt the end of the machine cycle the rate at which the pressure is reduced is also critical in many process

41、es. 在机器运行周期后段，在很多工序中压力等级的降低也是要求很严格的。FORCE CONTROLMotion and force control can thus be achieved using proportional valves, and in some cases the same valve can be used for both motion and force control. This is usually referred to as PQ control ie. the control of both pressure (P) and flow (Q).Furthe

42、rmore, all of these control functions can be achieved using electronic inputs to the valve thus providing a simple interface to the machine controller. 运动和力的控制因此能够通过使用比例阀来完成，同时在某些场合同一个阀能够同时用于运动控制和力控制。这通常被称为PQ”控制，也就是说同时控制压力和流量。此外，所有这些控制功能可以使用输入到阀的电子输入信号被完成，只需通过提供的到机械控制器的简单接口。ELECTRONIC CONTROL电子控制阀输入

43、信号 VALVE INPUT SIGNAL As described earlier, the electrical current to the solenoid of a proportional valve needs to be regulated and not just simply switched on or off as is the case with a conventional valve.作为简单描述，提供给比例阀电磁铁的电流需要被调节，不象应用常规阀的时仅有开关通或断那样简单。阀输入信号 VALVE INPUT SIGNAL In theory, this coul

44、d be achieved by using a dimmer switch type component (ie. a variable resistor). Practical problems such as heat generation and drift however mean that such a device would not normally be used except for the very simplest applications. 在理论上这可以通过使用一个调光开关式的元件来完成（例如，一个可变电阻）。实际上由于发热和漂移这样的设备一般不被使用，除非一些最简

45、单的应用中。24 V DC比例阀放大器 PROPORTIONAL VALVE AMPLIFIER Normally, the current flowing through the proportional solenoid will be controlled by some form of electronic amplifier. The amplifier itself will require a power supply (usually 12 or 24 VDC) and a command input signal.一般地，通过比例阀电磁铁地电流由一些形式地电子放大器控制。放大

46、器要求一个电源和一个命令输入信号。24 V DC比例阀放大器 PROPORTIONAL VALVE AMPLIFIER 放大器地输出（电流）由输入信号控制，所有零输入信号，电流输出也是零。The output of the amplifier (electrical current) is controlled by the input signal so with zero input the output current is also zero.24 V DC比例阀放大器 PROPORTIONAL VALVE AMPLIFIER Increasing the input signal t

47、o the amplifier results in a corresponding increase in output current to the valve solenoid.增加放大器地输入信号会导致输出到阀电磁铁的电流相应的增加。24 V DC比例阀放大器 PROPORTIONAL VALVE AMPLIFIER Increasing the input signal to the amplifier results in a corresponding increase in output current to the valve solenoid.24 V DC比例阀放大器 P

48、ROPORTIONAL VALVE AMPLIFIER Increasing the input signal to the amplifier results in a corresponding increase in output current to the valve solenoid.24 V DC比例阀放大器 PROPORTIONAL VALVE AMPLIFIER The relatively large current required to drive the valve solenoid (typically 2 to 3 amps) is provided by the

49、 power supply so the current required from the input signal device is very small (normally just a few milli-amps). The input control device can therefore be a simple potentiometer.一个相对较大的阀电磁铁输入电流（通常2到3安培）是由电源提供的，所有输入装置的电流要求非常小（一般仅有几毫安），因此输入控制装置可以是一个简单的电位计。24 V DC比例阀放大器 PROPORTIONAL VALVE AMPLIFIER I

50、n mobile applications the input device could by a joystick type potentiometer.在行走应用中，输入装置可以是一个操作杆型的电位计。24 V DC比例阀放大器 PROPORTIONAL VALVE AMPLIFIER In an increasing number of applications however, the input signal is generated by the machine controller itself (eg. a PLC - Programmable Logic Controller

51、). This can then be fed directly to the valve amplifier to generate the appropriate output.在越来越多的应用中，输入信号可以由控制器产生（例如，一个PLC可编程控制器），可以直接输入到阀放大器以产生适当的电流。伺服阀简介：伺服阀工作原理介绍：下面介绍两种主要的伺服阀工作原理：一、力反馈式电液伺服阀：1永久磁铁；2衔铁；3扭轴；4喷嘴；5弹簧片；6过滤器；7滑阀；8线圈；9轭铁力反馈式电液伺服阀的结构和原理如图所示，无信号电流输入时，衔铁和挡板处于中间位置。这时喷嘴4二腔的压力pa=pb，滑阀7二端压力相等

52、，滑阀处于零位。输入电流后，电磁力矩使衔铁2连同挡板偏转角。设为顺时针偏转，则由于挡板的偏移使papb，滑阀向右移动。滑阀的移动，通过反馈弹簧片又带动挡板和衔铁反方向旋转（逆时针），二喷嘴压力差又减小。在衔铁的原始平衡位置（无信号时的位置）附近，力矩马达的电磁力矩、滑阀二端压差通过弹簧片作用于衔铁的力矩以及喷嘴压力作用于挡板的力矩三者取得平衡，衔铁就不再运动。同时作用于滑阀上的油压力与反馈弹簧变形力相互平衡，滑阀在离开零位一段距离的位置上定位。这种依靠力矩平衡来决定滑阀位置的方式称为力反馈式。如果忽略喷嘴作用于挡板上的力，则马达电磁力矩与滑阀二端不平衡压力所产生的力矩平衡，弹簧片也只是受到电磁

53、力矩的作用。因此其变形，也就是滑阀离开零位的距离和电磁力矩成正比。同时由于力矩马达的电磁力矩和输入电流成正比，所以滑阀的位移与输入的电流成正比，也就是通过滑阀的流量与输入电流成正比，并且电流的极性决定液流的方向，这样便满足了对电液伺服阀的功能要求。力反馈式电液伺服阀的工作原理：由于采用了力反馈，力矩马达基本上在零位附近工作，只要求其输出电磁力矩与输入电流成正比（不象位置反馈中要求力矩马达衔铁位移和输入电流成正比），因此线性度易于达到。另外滑阀的位移量在电磁力矩一定的情况下，决定于反馈弹簧的刚度，滑阀位移量便于调节，这给设计带来了方便。采用了衔铁式力矩马达和喷嘴挡板使伺服阀结构极为紧凑，并且动特性好。但这种伺服阀工艺要求高，造价高，对于油的过滤精度的要求也较高。所以这种伺服阀适用于要求结构紧凑，动特性好的场合。力反馈式电液伺服阀的方框图如图：位置反馈式伺服阀：图为二级滑阀式位置反馈伺服阀结构。该类型电液伺服阀由电磁部分，控制滑阀和主滑阀组成。电磁部分是一只力马达，原理如前所述。动圈靠弹簧定位。前置放大器采用滑阀式（一级滑阀）。如图所示，在平衡位置（零位）时，压力油从P腔进入，分别通过P腔槽，阀套窗口