超高壓氣動比例減壓閥是怎么工作的?

【資料簡介】

摘要
高壓氣動系統因其*的功率密度高、瞬間膨脹性大、爆發力強、溫度適應范圍廣等特性而在、、武器裝備和氣動汽車等領域中得到應用。高壓氣動減壓閥是高壓氣動系統的關鍵元件，在中的超高壓自動化配氣和控制中有許多需求，但目前對高壓氣動系統的元件和控制系統進行系統、深入研究的卻很少。針對這一領域的空白和實際需求，本文對高壓氣動比例減壓閥進行了探索性研究。研制出一種超高壓氣動比例減壓閥，并系統分析了高壓氣動比例減壓閥的工作機理和控制方法。論文的主要內容如下：
*章概述了國內外高壓氣動技術的發展狀況，闡述了課題的研究意義。提出了本論文所要進行的主要工作及難點和創新之處。
第二章闡述了本課題研制的超高壓氣動比例減壓閥的原理和結構特點。提出主閥閥芯力反饋帶自密封特性的非*平衡方式和先導級采用串聯氣阻的滑閥式結構。對影響減壓閥特性的幾個關鍵因素進行了定性分析，指出比例電磁鐵的頻率響應特性、調壓腔的體積、先導閥閥口通流面積和氣動活塞的節流孔通徑是影響減壓閥特性的主要因素。
第三章深入研究減壓閥的工作機理及控制性能。建立了系統的數學模型，得出系統從輸入先導閥閥芯位移到系統輸出壓力的子系統的狀態方程：并對模型進行了線性化，得出了求系統傳遞函數的矩陣表達式。分析表明，閥的主體結構子系統是一個極復雜的非線性系統，其性能不僅與比例電磁鐵的性能和閥的結構參數有關，還與閥的輸入輸出壓力、工作溫度及主閥芯位移速度等工作狀態有關。
第四章在數學模型的基礎上運用Matlab的Simulink仿真工具對減壓閥這一高度非線性的系統進行了仿真分析。仿真分析了在輸入壓力為1 5 MPa的條件下，減壓閥的控制特性和主要結構參數對減壓閥性能的影響。仿真分析了減壓閥在高設計工作壓力31．5 MPa下，先導級泄漏對于減壓閥性能的影響。提出在先導級兩級節流[J采用不同的節流口寬度結構的方法，大大改善先導閥的工作狀況，降低先導泄漏對閥性能的影響。
第五章研制成功工作壓力在10MPa以上的氣動比例減壓閥，并建立了超高壓氣動比例減壓閥的實驗系統。在輸入壓力為14 MPs．條件下對減壓閥的動態性能、流量特性、壓力特性及控制性能進行了實驗研究。實驗證明，該減壓閥的設計在原理上是可行的，達到了一定的性能要求。在14 MPa的輸入壓力下，對于輸出壓力在1～12 MPa范圍內具有控制能力，壓力控制精度達3％以上，并且具有較好的流量特性。在6MPa下，負載流量從4 g／s變化到120 g／s，系統的控制性能穩定。實驗證明了仿真對于減壓閥控制性能分析的正確性，即高輸出壓力和低輸出壓力條件下的控制性能有較大差異，需要采用變增益的比例積分控制策略，也驗證了仿真中對調壓腔體積等參數對于減壓閻性能的影響的分析。
第六章對全文進行了總結，并對后續工作進行了展望。
關鍵詞：高壓，氣動，比例減壓閥，數學模型，仿真，串聯氣阻，實驗研究

ABSTRACT
High—pressure compressed air as work media that has some special advantages of
pollution free，high power density,large dispensability,strong burst force，large temperature
adaptability,and SO orl，has been applied to the aeronautics and astronautics domains，the
armament scopes and the compressed air powered vehicles aspects．However,up to no、u few
systematic and detailed researches On parts and control systems of high pressure pneumatic
have been done．
Aimed at application of the high pressure pneumatic system in the aerospace auto
distribution，principle and control methods of high pressure proportional valve are
systematically investigated，all of which have significant theoretical and practical values，
benefit to the development of the high pressure pneumatic system．The research work is
divided into the following chapters：
In chapter l，the history and current researches on hilgh-pressure valve ofnationally and
internationally are summarized．The origination and significance of this project are
introduced．The main research objects are proposed in this chapter,ang the major
difficulties ofthis project are summarized．
In chapter 2，a new type pneumatic proportional high-pressure valve is introduced．
Details of its structure characteristics and mechanics are described．In the pilot valve，a
proportional electro—magnet is used as pilot control component，and the control strategy of
electric closed—loop feedback is adopted． Such a structure as pilot valve’S series
air—resistances jS a special character of this valve． We analyze the factors that affect the
valve’s performances and point out that performances ofproportional electro-magnet，volume
of control chamber,area of pilot through-flow and diameter of pneumatic plunger’S orifice
are the major factors which determine 0n the valve’3 performances．
In chapter 3，a nonlinear mathematical model of the valve is built up to analyze the
influence of the structural parameters and controller parameters Oil the valvelS dynamic
characteristics．Based on the mathematical model，the state equations of this valve are got．
And get an open—loop transfer function by liberalized．As a result，system’S dynamical
performances are related to the valve’S structural parameters，the performance ofproportional
electro—magnet，the input pressure，the ouWut pressure，working temperature and the main
valve’S spool’S velocity．
In chapter 4，Matlab’S tools box Simulink is used tO analyze the valve’S performances．
According tO practical experimental conditions，input pressure is set at t5MPa，As a result，
volume of control chamber and diameter of pneumatic plunger’S orifice have great effec!on
折江大學壩士學位論文
system’S dynamical performances．And the influence of the pilot valve’S leakage On the
performance of pneumatic pressure proportional valve is analyzed under the condition of the
input pressure 3 1．5MPa，A method of using different widths of two throale windows is
proposed，which improves the working condition of pilot valve and reduces the influence of
pilot’S leakage
In chapter 5，the experimental system of high—pressure proportional valve is introduced．
’Fhe dynamical characteristic，discharge characteristic and pressure characteristic ofthis valve
are tested under the input pressure of 14MPa condition．As a result．this valve’S output
pressure ranges from 1MPa to 12MPa，when input pressure is 14MPa．And the control
performance is robust when the loads changed from 49／s to 1 209／s．The results．justify the
simulation about valve’S performances．Fixed parameters of PI controller can’t meet the
needs of control both in high output pressure and low output pressure．Volume of control
chamber and diameter of pneumatic plunger’S orifice have a great effect on system’S
dynamical performances．
In chapter 6，the research work is summarized and perspectives on the future are
presented．
Key words：High-pressure，Pneumatic，Proportional valve，Mathematic model，Simulation，
Series air-resistances，Experimental research
Tl