液压锤工作状态下活塞的力学模型与应力分析  

Mechanical Model and Stress Analysis of Hydraulic Hammer Piston under Work Condition

作　　者：谢良喜[1] 陶平[1] 

机构地区：[1]武汉科技大学

出　　处：《工程机械》2007年第5期44-46,共3页Construction Machinery and Equipment

摘　　要：液压锤工作环境非常恶劣,其中活塞是受力状况最为复杂、最容易失效的零件之一。研究了液压锤活塞在工作状态下的受力状况,建立了活塞加速行程的力学模型,获得了活塞撞击钎杆前的初始运动条件;应用有限元技术对活塞撞击钎杆的过程进行了刚柔体运动、非线性接触碰撞仿真,获得了活塞的应力云图及其关键点在撞击过程的应力变化曲线。分析表明,活塞撞击钎杆的持续时间非常短暂,冲击应力非常大,导致端部存在局部应力超出材料屈服极限。为了避免活塞因端面不均衡塑性变形而导致端部边缘破损、端面与轴线垂直度破坏等情况发生,需要对活塞端部结构进行改进。该分析结果已应用于某型液压锤设计,为提高活塞的使用寿命提供了技术指导。Work condition of a hydraulic hammer is very rigorous and its piston is one of the components bearing the most complicate loads and easiest to fail. Loading situation of hydraulic hammer piston under work condition is studied. Mechanical model of piston in accelerating process is set up and initial movement condition of the piston before impacting the rod is obtained. Rigid and flexible movement and nonlinear contact collision simulations of impact procedure between piston and rod are conducted with finite element technology. Stress nephogram and variation curve of piston in impact procedure are obtained. Analysis shows that impact time between piston and rod is very short but the impact stresses are huge,which results in a local stresses exceeding material yield strength limit at the end. So the piston end design must be improved in order to avoid edge damage and damage of axis perpendicularity due to uneven plastic deformation of the piston end surface. The analysis results have been applied to a hydraulic hammer design and provide a technical guidance for piston service life increase.

关 键 词：液压锤 活塞 有限元 ALGOR 

分 类 号：TH137.9[机械工程—机械制造及自动化]