切削热对热缩加长刀杆与刀具配合的承载能力的影响分析

Carrying Capacity Analysis of Lengthened Shrink-fit Holder and Cutting Tool Impacted by Cutting Heat

建立热缩加长刀杆与刀具配合的有限元模型,对稳定干切削状态下热缩式加长刀杆与刀具配合的温度、接触压力等热力学特性进行了分析。结果表明在高速切削状态下,热缩刀杆与刀具配合的承载能力是初始过盈量、高转速而产生的离心力以及因切削热而形成的瞬态温度场共同作用的结果。通过分析可知,承载能力主要取决于刀杆与刀具的初始过盈量和瞬态温度。随着切削时间的增长,刀杆与刀具的温度不断升高(由于对流与辐射散热,最后趋于稳定),热缩加长刀杆与刀具配合的接触压力减小,承载能力降低,所能传递的转矩被削弱。对热缩式刀杆的合理设计、选择和应用具有一定的理论和现实指导意义。

Established a finite element model of the matching of lengthened shrink-fit tool holder and cutting tool, then the thermodynamic characteristic of the matching of shrink-fit tool holder and cutting tool such as temperature and con- tact stress are analyzed on condition of the high speed and dry cutting state. The results show that the carrying capacity of lengthened shrink-fit tool holder and cutting tool is affected by the initial interference, centrifugal force and transient tem- perature. Through analysis, the carrying capacity of lengthened shrink-fit tool holder and cutting tool is depend on the ini- tial interference and transient temperature. With the growth of cutting time and temperature rising （ due to air convection, and finally stabilized）, the contact pressure and torque that can be transmitted of lengthened shrink fit tool holder and cut- ting tool has been reduced. Through the analysis of cutting heat effect on the transfer torque and it has a practical guiding significance, for the design of lengthened shrink-fit tool holder and the selection of the cutting tool.