基于等效静态载荷理论的机床运动部件轻量化设计

为保证机床的加工精度和切削效率,机床的运动部件需要较高的刚度和较轻的质量.以某型号磨床的主轴箱为研究对象,建立包含主轴箱、电主轴磨头和滚珠丝杠等部件的有限元柔性多体动力学模型,运用等效静态载荷理论将柔性多体动力学分析与静态结构优化理论相结合,采用拓扑优化技术对主轴箱进行轻量化设计.与传统静态载荷下的主轴箱结构拓扑优化设计相比,该方法更适用于机床运动部件的结构轻量化设计,优化后的主轴箱结构在保证静动态性能的前提下质量减轻8.5%.

Structural Design Optimization Method for Moving Parts of Machine Tool Based on Equivalent Static Load Theory

In order to ensure the machining accuracy and cutting efficiency,the moving parts of a machine tool not only need to be of higher stiffness in the cutting process,but also is required to have a light weight so as to reduce the inertia and deformation due to the self-weight during the fast moving process.As a typical design example,the headstock of a bevel gear grinder was studied.A flexible multi-body dynamics finite element model including the components of headstock,electric spindle grinding head,ballscrew and so on was established.The flexible multibody system dynamic analysis was combined with the static structure optimization theory based on the equivalent static load theory and the topology optimization design was performed on the headstock.Compared to the traditional topology optimization design of the headstock based on the static load,the proposed lightweight design method is suitable for moving parts of machine tool.The results show that the weight of the headstock is decreased by 8.5% while the static and dynamitic performance maintain nearly unchanged.