斜坡渐扩形节流槽对比例阀微动特性影响研究

针对现有U形节流槽的比例阀在小开口处，阀口过流面积变化梯度较为剧烈、流量增益较大，导致比例阀在小开口时会产生启动不平稳、响应速度较慢和流量控制精度较低的问题，提出一种节流槽形状为斜坡渐扩形的新阀芯。通过理论计算和模拟仿真的方法，对比分析了U形节流槽和斜坡渐扩形节流槽的过流面积变化梯度以及不同阀口开度下的位移特性、流量特性和阀口流动特性。由仿真结果可知，相较于U形节流槽，斜坡渐扩形节流槽在阀口开度为1mm时，阀芯位移响应时间缩短0.04s；在阀口开度为2mm时，阀芯位移响应时间缩短0.07s。且斜坡渐扩形节流槽在阀口开度较小时，稳态液动力更小，流动状态更稳定，造成的流动损耗也更小。最后进行了试验验证，由试验结果可知，斜坡渐扩形节流槽阀芯位移响应时间缩短0.08s，且阀芯流量响应特性曲线的线性度更好。通过对仿真和试验结果的对比分析可知，当节流槽形状为斜坡渐扩形时，阀芯在小开口处过流面积变化梯度较小，流量增益较为平稳，从而提高了阀的启动平稳性、响应速度和流量控制精度，改善了比例阀微动特性。

Influence of Slope-diverge-shaped Throttling Grooves on Micro-motion Characteristics of Proportional Valve

For the existing proportional valve with the U-shaped throttling grooves of the main spool, the discharge area change gradient of the valve port is more severe and the flow gain is large in the small opening, resulting in poor micro-motion characteristics such as unstable start, slower response and low flow control accuracy of the proportional valve in the small opening. A throttling grooves with slope-diverge-shaped was proposed. The discharge area change gradient of U-shaped throttling grooves and slope-diverge-shaped throttling grooves were compared and analyzed by theoretical calculation and simulation methods, as well as the displacement characteristics, flow characteristics and valve port flow characteristics under different valve port openings. It can be seen from the simulation results that compared with the U-shaped throttling grooves, the response time of the slope-diverge-shaped throttling grooves was shortened by 0.04s when the opening of the valve port was 1mm. When the opening of the valve port was 2mm, the displacement response time was shortened by 0.07s. And when the slope-diverge-shaped throttling grooves valve was ported at the small opening, its steady-state hydraulic power was smaller, the flow state was more stable, and the flow loss was smaller. And the experimental results showed that the displacement response time of the spool of the slope-diverge-shaped throttling grooves was shortened by 0.08s, and the linearity of the flow response characteristic curve was better. Finally, through the comparative analysis of the simulation and experimental results, it can be seen that slope-diverge-shaped throttling grooves, the discharge area change gradient of the main valve core was smoothly in the small opening, and the flow gain was relatively stable, which improved the smoothness of valve start-up, speed of response and flow control accuracy. In summary, the slope-diverge-shaped throttling grooves realized the improvement of the micro-motion characteristics of the proportional valve.