机床与液压
機床與液壓
궤상여액압
MACHINE TOOL & HYDRAULICS
2015年
6期
59-63
,共5页
伺服阀%动压反馈%时间常数%层流%设计方法
伺服閥%動壓反饋%時間常數%層流%設計方法
사복벌%동압반궤%시간상수%층류%설계방법
Servo valve%Dynamic pressure feedback%Time constant%Laminar flow%Design method
动压反馈技术应用于喷嘴挡板伺服阀中可以显著改善其响应特性。在伺服阀中实现动压反馈最可靠的方法是在其中增加一个动压反馈装置。但根据传统设计方法,加工出的动压反馈伺服阀中的关键变量时间常数通常与设计值相差很大,主要是因为传统设计方法错误地将动压反馈装置中喷嘴出口处的油液认为是紊流。根据理论推导和实验研究,证实了喷嘴出油其实为层流;进而对动压反馈伺服阀时间常数的计算方法重新进行了梳理,该方法对于动压反馈伺服阀的设计具有重要意义。
動壓反饋技術應用于噴嘴擋闆伺服閥中可以顯著改善其響應特性。在伺服閥中實現動壓反饋最可靠的方法是在其中增加一箇動壓反饋裝置。但根據傳統設計方法,加工齣的動壓反饋伺服閥中的關鍵變量時間常數通常與設計值相差很大,主要是因為傳統設計方法錯誤地將動壓反饋裝置中噴嘴齣口處的油液認為是紊流。根據理論推導和實驗研究,證實瞭噴嘴齣油其實為層流;進而對動壓反饋伺服閥時間常數的計算方法重新進行瞭梳理,該方法對于動壓反饋伺服閥的設計具有重要意義。
동압반궤기술응용우분취당판사복벌중가이현저개선기향응특성。재사복벌중실현동압반궤최가고적방법시재기중증가일개동압반궤장치。단근거전통설계방법,가공출적동압반궤사복벌중적관건변량시간상수통상여설계치상차흔대,주요시인위전통설계방법착오지장동압반궤장치중분취출구처적유액인위시문류。근거이론추도화실험연구,증실료분취출유기실위층류;진이대동압반궤사복벌시간상수적계산방법중신진행료소리,해방법대우동압반궤사복벌적설계구유중요의의。
Dynamic pressure feedback (DPF)technology is usually used in a hydraulic servo system to improve its response characteristics.The most reliable way to realize the feedback is to integrate a mechanical DPF device in a flow control servo valve.However,as a key parameter,the time constant is usually big different between the desired and actual valve if the valve has been designed by traditional method.We analyze this reason which is mainly caused by the wrong assumption that oil jetting from feedback nozzles is in the turbulent flow region.Based on the theoretical analysis and experimental tests,it has been confirmed that the fluid flow is indeed in laminar flow region.Therefore,a new method to evaluate the time constant could be obtained,which will be very useful for the design of a DPF device.