直动-导控一体化2D电液比例换向阀关键技术的基础研究

The 2D electro-hydraulic proportional directional valve is composed of 2D directional valve（flow valve）， compression-torsion coupling and proportional electromagnet. Under the normal working pressure,the magnetic force of the proportional solenoid rotates the spool through the compression-torsion coupling and induces the pressure of the sesititive chamber on the two side to vary differentially.Consequently, the spool axially slides under the hydrostatic imbalanced force. As the spool moves forward ,it rotates inversely and the pressure of the sensitive chamber recovers and returns to its previous value. In this process,the spool arrives at a new axial position and the proportional contol to the valve openings is achieved. While the working pressure of the system is zero,the spool is proportionally driven by the magnetic force directly. Thus, the 2D electro-hydraulic proportional directional valve can fuctions both as a pilot directional valve or direct actuated valve. The compression-torsion coupling is used to realize motion conversion and amplify the thrust force of proportional electromagnet, therefore the unfavorable influence of friction force between spool and valve sleeve on proportional characteristics can be effectively overcome. The function of pilot stage of electro-hydraulic proportional directional valve is achieved by double degrees of freedom of spool so that the unfavorable influence of fluid force can be effectively eliminated and the axial positioning precision of spool can be improved. The theoretical basis for the realization of compression-torsion amplified driven technology will be established through deep study of performance and structure optimal design of compression-torsion coupling; The theoretical basis of structure design and optimization will be provided through the study of stability, static and dynamic characteristics of 2D directional valve under both open and closed loop mode; The engineering application example will be provided through the experimental study for static and dynamic characteristics and validation of function principle of typical 2D electro-hydraulic proportional directional valve prototype.

2D电液比例换向阀由2D换向阀、压扭联轴器和比例电磁铁等组成。正常工作压力下，比例电磁铁输出的推力通过压扭联轴器使阀心转动，阀敏感腔的压力差动变化，驱动阀心轴向移动，与此同时阀心反向转动，敏感腔的压力又逐渐恢复为原来的值，阀心到达一个新的平衡位置，实现对阀心位移比例控制；当工作压力为零时，则由比例电磁铁直接推动阀心。该阀兼具直动式和导控式比例阀的双重功能。采用压扭联轴器将比例电磁铁对阀心驱动力放大，有效地克服了摩擦力等对阀比例特性所造成的不利影响；采用阀心双运动自由度实现导控功能，有效地克服液动力，提高了阀心的轴向定位精度；通过对压扭联轴器性能和结构优化设计的深入研究，为压扭放大驱动技术的实现奠定理论基础；通过对开环和闭环下的2D换向阀静、动态特性以及稳定性的研究，为其结构设计和优化提供理论依据；对典型的2D电液比例换向阀样机进行动、静特性以及功能原理验证的实验研究，为其工程应用提供范例。

电液比例换向（节流）阀以其结构简单、对介质清洁度无特殊要求、制造成本低、可简化液压系统以及能耗低等特点，已成为电液比例控制系统中应用最广泛的基础元件之一。传统的直动式电液比例换向（节流）阀由于受比例电磁铁推力的制约，其流量和压力不能达到较高的水平，致使目前对一些大流量的应用场合都必须采用导控型电液比例换向阀，而导控型电液比例换向（节流）阀结构复杂，不能像直动式电液比例换向（节流）阀一样在零压情况下工作。为此，提出了一种2D电液比例换向（节流））阀。该阀由压扭联轴器、2D换向阀和比例电磁铁三者共轴联结构成，正常工作压力下，比例电磁铁输出的推力通过压扭联轴器使阀心转动，阀敏感腔的压力差动变化，驱动阀芯轴向移动，与此同时阀芯反向转动，敏感腔的压力又逐渐恢复为原来的值，阀芯到达一个新的平衡位置，实现对阀芯位移比例控制；当工作压力为零时，则由比例电磁铁直接推动阀芯。通过压扭联轴器的轴向推力转换为切向驱动力，并进行放大，有效地克服了阀芯和阀孔之间的摩擦力等非线性因素所造成的不利影响；采用阀芯的旋转和滑动的双运动自由度实现导控型电液比例换向阀功能，有效地克服液动力（伯努利力）所造成的不利影响，提高了阀芯的轴向定位精度。通过对压扭联轴器性能和结构优化设计的深入研究，为压扭放大驱动技术的实现奠定理论基础；通过对开环和闭环下的2D 换向（节流）阀静、动态特性以及稳定性的研究，为其结构设计和优化提供理论依据。该阀结构简单、原理先进，不仅具有普通的导控型电液比例换向阀流量大、工作压力高特点，而且在零压（失压）下也可以像直动式比例换向阀那样实现比例控制功能。本报告的研究将有效地推动电液比例控制技术的进步和发展，并推动相关行业的发展，具有重要的理论意义和实际工程应用前景。