超高壓氣動(dòng)比例減壓閥是怎么工作的?

摘要
高壓氣動(dòng)系統(tǒng)因其*的功率密度高、瞬間膨脹性大、爆發(fā)力強(qiáng)、溫度適應(yīng)范圍廣等特性而在、、武器裝備和氣動(dòng)汽車等領(lǐng)域中得到應(yīng)用。高壓氣動(dòng)減壓閥是高壓氣動(dòng)系統(tǒng)的關(guān)鍵元件，在中的超高壓自動(dòng)化配氣和控制中有許多需求，但目前對(duì)高壓氣動(dòng)系統(tǒng)的元件和控制系統(tǒng)進(jìn)行系統(tǒng)、深入研究的卻很少。針對(duì)這一領(lǐng)域的空白和實(shí)際需求，本文對(duì)高壓氣動(dòng)比例減壓閥進(jìn)行了探索性研究。研制出一種超高壓氣動(dòng)比例減壓閥，并系統(tǒng)分析了高壓氣動(dòng)比例減壓閥的工作機(jī)理和控制方法。論文的主要內(nèi)容如下：
*章概述了國(guó)內(nèi)外高壓氣動(dòng)技術(shù)的發(fā)展?fàn)顩r，闡述了課題的研究意義。提出了本論文所要進(jìn)行的主要工作及難點(diǎn)和創(chuàng)新之處。
第二章闡述了本課題研制的超高壓氣動(dòng)比例減壓閥的原理和結(jié)構(gòu)特點(diǎn)。提出主閥閥芯力反饋帶自密封特性的非*平衡方式和先導(dǎo)級(jí)采用串聯(lián)氣阻的滑閥式結(jié)構(gòu)。對(duì)影響減壓閥特性的幾個(gè)關(guān)鍵因素進(jìn)行了定性分析，指出比例電磁鐵的頻率響應(yīng)特性、調(diào)壓腔的體積、先導(dǎo)閥閥口通流面積和氣動(dòng)活塞的節(jié)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(jī)理及控制性能。建立了系統(tǒng)的數(shù)學(xué)模型，得出系統(tǒng)從輸入先導(dǎo)閥閥芯位移到系統(tǒng)輸出壓力的子系統(tǒng)的狀態(tài)方程：并對(duì)模型進(jìn)行了線性化，得出了求系統(tǒng)傳遞函數(shù)的矩陣表達(dá)式。分析表明，閥的主體結(jié)構(gòu)子系統(tǒng)是一個(gè)極復(fù)雜的非線性系統(tǒng)，其性能不僅與比例電磁鐵的性能和閥的結(jié)構(gòu)參數(shù)有關(guān)，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(tài)有關(guān)。
第四章在數(shù)學(xué)模型的基礎(chǔ)上運(yùn)用Matlab的Simulink仿真工具對(duì)減壓閥這一高度非線性的系統(tǒng)進(jìn)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(jié)構(gòu)參數(shù)對(duì)減壓閥性能的影響。仿真分析了減壓閥在高設(shè)計(jì)工作壓力31．5 MPa下，先導(dǎo)級(jí)泄漏對(duì)于減壓閥性能的影響。提出在先導(dǎo)級(jí)兩級(jí)節(jié)流[J采用不同的節(jié)流口寬度結(jié)構(gòu)的方法，大大改善先導(dǎo)閥的工作狀況，降低先導(dǎo)泄漏對(duì)閥性能的影響。
第五章研制成功工作壓力在10MPa以上的氣動(dòng)比例減壓閥，并建立了超高壓氣動(dòng)比例減壓閥的實(shí)驗(yàn)系統(tǒng)。在輸入壓力為14 MPs．條件下對(duì)減壓閥的動(dòng)態(tài)性能、流量特性、壓力特性及控制性能進(jìn)行了實(shí)驗(yàn)研究。實(shí)驗(yàn)證明，該減壓閥的設(shè)計(jì)在原理上是可行的，達(dá)到了一定的性能要求。在14 MPa的輸入壓力下，對(duì)于輸出壓力在1～12 MPa范圍內(nèi)具有控制能力，壓力控制精度達(dá)3％以上，并且具有較好的流量特性。在6MPa下，負(fù)載流量從4 g／s變化到120 g／s，系統(tǒng)的控制性能穩(wěn)定。實(shí)驗(yàn)證明了仿真對(duì)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?cè)鲆娴谋壤e分控制策略，也驗(yàn)證了仿真中對(duì)調(diào)壓腔體積等參數(shù)對(duì)于減壓閻性能的影響的分析。
第六章對(duì)全文進(jìn)行了總結(jié)，并對(duì)后續(xù)工作進(jìn)行了展望。
關(guān)鍵詞：高壓，氣動(dòng)，比例減壓閥，數(shù)學(xué)模型，仿真，串聯(lián)氣阻，實(shí)驗(yàn)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(xué)壩士學(xué)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