油缸缓冲结构参数对缓冲性能的影响分析

摘要

该文针对某型液压挖掘机因油缸前腔缓冲造成的机械冲击问题,采用能量法对缓冲压力测试曲线进行分析,确定了冲击产生原因.基于油缸前腔缓冲结构将缓冲过程划分为三个阶段,建立流量方程并对影响缓冲压力变化趋势的主要结构参数进行了分析.依据系统流量与油缸结构建立数学模型计算获得缓冲时间-速度函数,同时建立缓冲结构CFD仿真模型.以缓冲时间-速度函数为输入条件,通过仿真分析重点研究了缓冲套斜面长度、缓冲阻尼孔孔径对缓冲性能的影响,并确定了缓冲结构参数优化值.仿真结果表明:合理缩短缓冲斜面长度并扩大缓冲阻尼孔孔径,可以有效控制缓冲压力曲线变化趋势,满足缓冲峰值压力控制要求的同时降低机械冲击.仿真结果为该型油缸缓冲结构的优化提供了参考.%According to the mechanical impact caused by the cylinder buffering structure on the excavator, use the energy method to analysis the buffering pressure curve, confirm the causes of impact. Based on the buffering structure divide the buffering process to three phases, es-tablish the flow-equation and analysis the influence of main buffering structure parameters to the buffering pressure curve. Based on the sys-tem flow and structure of hydraulic cylinder establish the mathematics model and calculate the buffering time-velocity function, at the same time establish the CFD simulation model of buffering structure. Use buffering time-velocity as input, study the influence of inclined plane length of buffering ring and diameter of buffering orifice to the buffering performance by simulation. Ascertain the optimization parameters of buffering structure. The simulation results showed:shorten the inclined plane length of buffering ring and enlarge the diameter of buffer-ing orifice can control the buffering pressure effectively, to satisfied the peak pressure requirement and at the same time to reduce the me-chanical impact. The simulation results provided the referrence to optimize the buffering structure of this cylinder.