闭式泵控单出杆液压缸静动态流量实时匹配理论与方法

Compared with the valve control cylinder, the pump control cylinder system has the advantages of compact structure and higher energy efficiency, which is the current hot research in the hydraulic actuator control field. However, for that the difference between the inlet flow and outlet flow of the single rod cylinder is very big, a single hydraulic pump can’t match the asymmetric flow of the single rod cylinder. The existing technologies need to use auxiliary pump or hydraulic valve to control the movement of the single rod cylinder, which has the problems that the technologies are complex, the energy use efficiency is low and the expense is high, which has been a technical difficulty to constraint the application of the single rod cylinder system.For this, a single rod hydraulic cylinder control loop controlled by combination asymmetric variable displacement gear pump with three thrust windows is proposed, which the ratio of input flow and output flow of the asymmetric gear pump can match the two cavities area ratio of the single rod cylinder, and the variable displacement control method of the gear pump can real-time compensate and match the dynamic flow deviation caused by the leakage and oil compression of the system. Focusing on two science questions of the flow compensation mechanism and control method of the asymmetric gear pump control single rod cylinder system, the rule of energy transfer, conversion and function, the flow and pressure pulsation, the energy efficiency performance of the asymmetric gear pump, the static and dynamic characteristics of variable displacement control mechanism, the speed and displacement control system and the energy efficiency performance of pump control single rod cylinder will be researched, new principles and methods of the operation of pump control single rod cylinder with low energy consumption will be searched, which will provide technical support for the green development of the elector-hydraulic system.

与阀控缸相比，泵控缸系统结构紧凑、具有极高的能量效率，是液压执行器控制领域的研究热点，但由于单出杆液压缸进出油液流量差别大，造成单液压泵无法匹配单出杆缸不对称流量。现有技术需采用辅助泵或液压阀才能控制其运动，存在技术复杂、能量利用率低、成本高等问题，是制约泵控单出杆液压缸系统推广应用的技术难点。对此提出组合式三配流窗口变排量非对称齿轮泵控单出杆液压缸回路，其中非对称齿轮泵的吸排油流量之比与单出杆液压缸两腔面积比相匹配，并且齿轮泵变排量调节方法可实时补偿匹配系统泄露、油液压缩造成的动态流量偏差。围绕非对称齿轮泵控单出杆缸系统流量补偿机制及调控方法，系统能量传递转换及作用规律两个科学问题，对非对称齿轮泵流量、压力脉动及能效特性，变排量调控机构动静态特性，泵控单出杆缸位置、速度控制系统及能量效率特性展开研究，探索泵控单出杆液压缸系统低能耗运行的新原理和新方法，为实现电液系统绿色发展提供技术支撑。

本项目针对闭式泵控单出杆液压缸流量不匹配问题，充分结合齿轮泵自吸能力强、结构简单等优点，提出一种非对称变排量齿轮泵控单出杆液压缸系统，通过对变排量非对称齿轮泵的研究，实现泵控单出杆液压缸系统不对称流量的静动态补偿，提高系统动态响应及能量效率。.结合单出杆液压缸特点，提出了组合式非对称齿轮泵原理，对非对称齿轮泵流场特性进行了可视化仿真，设计优化了非对称齿轮泵结构参数；建立了非对称齿轮泵联合仿真模型和试验台，分析了非对称齿轮泵流量和压力脉动特性，获得了不同工况下非对称齿轮泵的能效特性，结果表明，非对称齿轮泵流量和压力脉动较小，且可获得较高的能量效率。提出了一种变困油区面积的排量控制方法，通过调整增设的滑块位置，实现齿轮泵排量微调，建立了变排量齿轮泵仿真模型和试验台，对变量齿轮泵内部流场特性进行了研究分析了影响齿轮泵排量调控范围的因素，结果表明，设计的排量控制方法可实现齿轮泵排量在88%-100%之间进行调节。建立了非对称齿轮泵控单出杆液压缸系统仿真模型，根据单出杆缸负载工况变化及各部件的特性，获得了回路元件参数匹配设置规律，提高了单出杆液压缸控制性能。对单出杆液压缸的速度阶跃响应特性、位置控制特性及能效特性进行了仿真分析和试验研究，结果表明，提出的闭式泵控单出杆液压缸系统可实现四象限工况下的稳定运行，具有良好的速度和位置控制特性，与传统闭式泵控系统相比，具有较高的能量效率。.本项目的研究成果可在注塑机、筑路机、装载机、联合收割机等中小功率设备得到广泛应用，可提高液压系统效率、设备安全性和可靠性，减小装机功率、降低噪声，提高国产装备的国际竞争力。