液压自由活塞发动机频率阀工作特性

Operation characteristics of a frequency valve for hydraulic free-piston engines

针对单活塞液压自由活塞发动机工作频率控制的需要,给出一种频率阀结构和连接方式,对频率开启过程的两个阶段和关闭过程进行理论分析,建立了频率阀动态特性压力测试系统,并对频率控制开关过程进行试验研究。研究结果表明,提出的频率阀具有大通流能力高响应特征,主阀的大通径保证了频率阀的通流能力,先导阀的高响应和次阀的大通径实现了频率阀的高响应。频率阀开启时间延迟包括从先导阀控制信号发出到先导阀开始动作之间的间隔和从先导阀开始动作到主阀芯开始动作之间的间隔。

To control the working frequency of a single piston hydraulic free-piston engine,the configuration and connection of a novel frequency valve were presented.The two steps in the process of opening and the closing action of the valve were investigated theoretically.The pressure test system for the valve dynamic characteristics was developed and the on-off characteristics were analyzed.The results indicate that the novel valve has operation characteristics that contain large flow area and high response.The large flow area is gained by a large diameter of the main spool.The higher response of the pilot valve and the large diameter of the secondary spool satisfy the high response requirement of the frequency valve.The time delay in the process of opening includes two parts which are the time delay between the output of the signal,and the time delay between the action of the pilot valve and the main valve.