甘蔗收获机多路阀阀芯的温升及热变形仿真分析

Simulation Analysis of Temperature Rise and Thermal Deformation of Multi-way Valve Spool in Sugarcane Harvester

多路阀是甘蔗收获机械液压系统的核心元件,用于控制多个工作装置的协同作业。针对其阀口压差变化大,节流温升明显,易造成阀芯变形卡滞的问题,对多路阀阀芯进行了流固热耦合仿真研究。利用Design Model软件抽取对应流道,并建立不同开度的多路阀流场仿真模型,导入ANSYS Workbench平台进行不同工况下的流固热耦合仿真,分析对比了双U形和三角形节流槽在不同开度、不同进出口压差工况下,多路阀内部流场的流体速度、阀芯温度及变形的情况。结果表明:双U形、三角形节流槽阀芯最高温度始终在节流槽处;随着阀进出口压差增加,油液的最大流速以及两种节流槽型阀芯的最高温度和最大形变量增大,但三角节流槽型阀芯变形相对较小;随着阀口开度的增加,三角节流槽型阀芯温度及最大形变量均小于双U形节流槽阀芯;三角节流槽型阀芯的最大形变量较双U节流槽型阀芯小25.1%。为农业机械多路阀阀芯节流槽设计提供了理论依据。

Multi-way valve is the core component of the hydraulic system of sugarcane harvesting machinery,which is used to control the cooperative operation of multiple working devices.Aiming at the problems of large pressure difference variation at the valve port,obvious throttling temperature rise,and easy to cause spool deformation and stagnation,a fluid-solid-thermal coupling simulation study was carried out on the spool of the multi-way valve.Firstly,Design Model software is used to extract the corresponding flow paths and establish the simulation model of the flow field of multi-way valves with different openings,and then imported into ANSYS Workbench platform to carry out the fluid-solid-thermal coupling simulation under different working conditions.Finally,it analyzed and compared the fluid velocity,spool temperature and deformation of the internal flow field of the multi-way valve with double U-shaped and triangular throttling grooves under different openings and different inlet and outlet differential pressure conditions.The results of the study showed that the highest temperature of the double U-shaped,triangular throttle groove spool was always at the throttle groove.As the pressure difference between the valve inlet and outlet increases,the maximum flow rate of the oil,as well as the highest temperature and maximum deformation of the spool of the two types of throttle groove forms increase,and the deformation of the spool of the triangular throttle groove is smaller;With the increase of spool opening,spool temperature and maximum deformation of the triangular throttle groove spool are smaller than that of the double U-shaped throttle groove spool;The maximum deformation of the triangular throttle groove spool decreases by 25.1%compared with that of the double U-shaped throttle groove spool.This study provides a reference for the design of spool throttling grooves of multi-way valves for agricultural machinery.