摘要
为实现对液压缸活塞杆振动中心平衡位置偏置量的精确控制,提出2D阀与电液数字阀并联机构的新方案.在产生相同流量平均值的条件下,将并联机构等效为正开口滑阀,求解出振动中心的平衡位置,然后将并联数字阀等效为恒定负载,推导出偏置控制下振动波形的解析解.在5～200Hz范围内进行振动疲劳试验,试验结果表明:当2D阀阀开口一定时,并联数字阀阀口与活塞杆振动中心平衡位置点成线性关系,但偏置量不会大于最大振幅,振动波形类似正弦波;当并联数字阀阀口一定时,随2D阀阀口面积系数的增大,偏置的平衡位置点减小,振动的最大位置点呈先减小再增大的规律;当振动频率为200Hz、并联数字阀开口面积占最大并联阀阀口面积的25%时,振动的最大位置点在2D阀阀口面积的20%处最小.这一并联机构不仅能提高频响,保证电液激振器工作频率和激振幅值的分别控制,而且能够实现偏载量的独立、精确控制.
To precisely control the bias position of an electro-hydraulic vibration exciter,a scheme of a digital servo valve connected in parallel with a two-dimensional valve（2Dvalve）is proposed and investigated.The mathematical model of the electro-hydraulic vibration exciter is constructed,a vibration central position is analytically derived by assuming that the paralleled valves are equivalent to a single slide valve with neutral positive opening and identical time-average flow rate.Then the analytic solutions to excited waveforms superimposed on the bias position are further obtained.The experimental system is established to verify the theoretical analysis in the range of 5-200Hz.The results reveal that when the opening area of 2Dvalve is constant,the bias position follows a linear relation with the throttling areas of the parallel valve,but there is a virtual limitation on the maximum position.The excited waveform is close to the sinusoidal waveform.In the same opening area of the parallel valve,the bias position is reduced as the area coefficient of 2Dvalve increases.In this process,maximum position of vibration goes up after a sharp reduction.When the frequency is 200Hz and throttling area of parallel valve is 25%,the maximum bias poison gets the minimum at 20% of the throttling area of 2Dvalve.The proposed scheme ensures not only the frequency and the amplitude to be controlled independently but also the bias position to be adjusted precisely.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2010年第9期82-86,127,共6页
Journal of Xi'an Jiaotong University
基金
国家自然科学基金资助项目(50675204)
浙江省自然科学基金重大专项资助项目(D1080667)
关键词
2D阀
偏置控制
振动波形
two-dimensional valve
bias control
excited waveform
