非对称液压缸具有占据空间小、制造简单且成本低廉等优点，在液压系统中应用极为广泛。但是，在液压伺服系统中，特别是在采用零开口伺服阀控制的阀控缸系统中，由于非对称液压缸活塞两侧的承压面积不同，当伺服阀阀芯在零开口附近做振荡时，液压缸两腔交替供油，活塞运动方向发生交替变化，此时液压缸两腔会产生压力突跳，产生系统振荡及爆振现象，严重时导致管道破裂等情况发生，不仅影响系统的稳定性，使系统无法正常工作，甚至导致液压系统及主机结构破坏。该问题在采用液压系统计算机仿真设计时很容易被忽略，造成设计失败。分析一个实际零开口对称伺服阀控不对称液压缸的液压系统设计案例，对对称阀控制不对称液压缸进行了不相容性分析，明确系统产生“爆振”的原因，以及提出该设计失败后的改进方案。%Virtues of unsymmetrical cylinder are needing small space ,easy manufacturing ,low cost,and etc.,thus it is widely ap-plied in hydraulic system .But because of differences in the compression area of unsymmetry oil cylinder piston on each side ,when use zero opening hydraulic valve to control unsymmetrical hydraulic cylinder ,servo valve spool will oscillate near the zero open-ing .Therefore hydraulic oil enter two cavities alternately ,the piston movement direction changes alternately ,two cavities of the hy-draulic cylinder will produce pressure jump .The hydraulic system will oscillate or generate blasting vibration phenomenon ,even lead to pipeline rupture etc ..Those will cause the system ’ s job characteristics become instable and unable to work ,the hydraulic system and equipment will be damaged .This phenomenon is easy to be neglected in computer aided design and simulation of hy-draulic system,which cause to design failure .Gives a actual design case of zero opening symmetrical hydraulic valve to control unsymmetrical hydraulic cylinder ,incompatibility analysis is conduct to assess this situation .The reason of system blasting vibra-tion phenomenon is confirmed ,improvement program is proposed finally .
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