【作者】 王涛；

【导师】 董彦良；

【作者基本信息】 哈尔滨工业大学 ， 机械（专业学位）， 2023， 硕士

【摘要】 高速开关阀作为数字液压元件核心,具有控制方便、响应快、抗污染能力强等优点。相较于电液比例阀,将高速开关阀应用于比例换向阀先导级,不仅降低了成本,还能在较为恶劣的环境中工作。目前国内应用于比例换向阀先导级的高速开关阀产品较少,结构较为复杂,针对高速开关阀多物理场下的工作特性研究较少。本文围绕先导级用高速开关阀进行结构设计与理论分析,通过仿真完成阀的特性研究与优化,试验表明课题所设计的高速开关阀响应快,满足指标要求。本文设计的一体式高速开关阀响应快,结构简单、紧凑,能够驱动主阀芯位移,实现比例功能。首先,结合使用场景确定了高速开关阀整体结构与材料,并对高速开关阀电磁铁以及其他主要零件进行初步设计;对高速开关阀进行理论建模与分析,结合理论对高速开关阀工作机理进行深入研究,并基于Amesim完成高速开关阀的初步仿真与分析。其次,使用Maxwell软件建立高速开关阀电磁铁仿真模型。通过静态电磁仿真研究总磁势与结构参数对电磁铁静态电磁力的影响;通过瞬态电磁仿真研究衔铁结构参数与弹簧参数对电磁铁动态特性的影响;结合仿真结果确定电磁铁参数,通过提高电流密度以及接入反向电压的方法分别实现阀的开、关响应指标,并使用磁-热耦合仿真方法验证高速开关阀温升符合要求。然后,利用CFD方法对高速开关阀进行流场仿真分析。通过稳态流场仿真研究高速开关阀的稳态流场以及阀口流量情况,指出阀座节流口处可能产生气穴;通过编写UDF实现电磁力、流体力以及弹簧力共同作用下阀芯的运动,完成阀芯与流场的耦合仿真,获得更为准确的流场变化与阀芯运动等情况,明确不同弹簧刚度对阀芯运动以及流场变化的影响;使用多相流仿真验证节流口空化现象,并通过改进阀座节流口结构以抑制空化。最后,通过Amesim与Maxwell联合仿真完成高速开关阀以及比例换向阀的仿真,验证高速开关阀对主阀的比例控制功能;通过试验验证高速开关阀设计的可行性以及仿真的正确性。本文为丰富先导级用高速开关阀产品做出了努力。更多还原

【Abstract】 As the core of digital hydraulic components,high-speed switching valve has the advantages of convenient control,fast response,and strong anti-pollution ability.Compared with electro-hydraulic proportional valves,applying high-speed switching valves to the pilot stage of proportional directional valves not only reduces costs,but also works in harsher environments.At present,there are few high-speed switching valve products used in the pilot stage in China,and the structure is relatively complicated.Meanwhile,there are few studies on the characteristics of high-speed switching valves under multiple physical fields.In this paper,the structural design and theoretical analysis of the high-speed on-off valve for the pilot stage are carried out,and the characteristics of the valve are studied and optimized through simulation.The integrated high-speed switching valve designed in this paper has fast response,simple and compact structure,and can drive the displacement of the spool to realize the proportional function.First of all,based on the application scenarios,the overall structure and materials of the high-speed switching valve were determined,and preliminary designs of the electromagnetic coil and key components were conducted.A theoretical model of the high-speed switching valve system was established.By combining theoretical analysis,a thorough investigation into the operating mechanism of the high-speed switching valve was conducted.Subsequently,a preliminary simulation of the high-speed switching valve was performed by Amesim.Secondly,the electromagnetic simulation model of electromagnet was developed using Maxwell.Static electromagnetic simulations were performed to investigate the influence of total magnetic potential and structural parameters on the static electromagnetic force of the electromagnet.Transient electromagnetic simulations were conducted to study the impact of armature structural parameters and spring parameters on the dynamic response of the electromagnet.Based on the comprehensive analysis results,the electromagnet parameters were determined.By increasing the current density and applying reverse voltage,the desired response indicators of the valve were achieved.Subsequently,magnetic-thermal coupled simulations were carried out to verify that the temperature rise of the high-speed switching valve meets the design requirements.Then,Computational Fluid Dynamics(CFD)method was employed to simulate the flow field of the high-speed switching valve.Through steady-state flow field simulations,the flow field and valve orifice flow conditions of the high-speed switching valve were investigated,indicating the possible formation of cavitation at the valve seat throttling section.By developing User-Defined Functions(UDFs),the motion of the spool under the combined effects of electromagnetic force,fluid force,and spring force was simulated,achieving transient simulations that coupled the spool motion with the flow field.This approach provided more accurate information on the changes in the flow field and the spool motion.The influence of different spring stiffness values on the spool motion and flow field was clearly identified.Additionally,multiphase flow simulations were conducted to verify the cavitation phenomenon at the throttling section,and improvements were made to the valve seat throttling structure to suppress cavitation formation.Finally,a comprehensive system simulation of the high-speed switching valve and directional valve was conducted by combining Amesim and Maxwell simulations.This joint simulation verified the proportional control capability of the high-speed switching valve on the spool of the directional valve.Furthermore,experimental testing of the highspeed switching valve was performed to validate the feasibility of the valve design and the accuracy of the simulations.This research has made significant contributions to enriching the range of high-speed switching valve products for use in the pilot stage.更多还原