The connection characteristics of HSK tool holder-spindle system have great influences on machining precision and security of computer numerical control machine tools. In order to predict dynamic behaviors and avoid connection failure of HSK tool holder-spindle system, a nominal radial stiffness prediction model for HSK tool holder-spindle flange interface is constructed. Contact stress of spindle and HSK tool holder can be obtained by considering actual interference and actual clamping force. Considering elastic contact deformation, the plastic contact deformation, and two different regimes of elastoplastic contact deformation, a fractal model of nominal contact stiffness of HSK tool holder-spindle flange interface is proposed. In order to prove the rationality of the model, the tests are validated by a self-designed equipment. The effects of different parameters to the maximal permissible rotational speed, critical bending moment, and nominal radial stiffness of HSK tool holder-spindle connection system are researched. The results can be used as an instruction for the application of HSK tool holder and optimization of geometry parameters.

HSK刀柄-主轴系统的连接特性对计算机数控机床的加工精度和安全性影响很大。为了预测动态行为并避免HSK刀柄-主轴系统的连接故障，构建了HSK刀柄-主轴法兰接口的名义径向刚度预测模型。主轴和HSK刀架的接触应力可通过考虑实际干扰和实际夹紧力来获得。考虑到弹性接触变形，塑性接触变形以及两种不同的弹塑性接触变形机制，提出了HSK刀柄-主轴法兰接口名义接触刚度的分形模型。为了证明该模型的合理性，测试由一台自行设计的设备进行了验证。研究了不同参数对HSK刀柄-主轴连接系统的最大允许转速，临界弯矩和标称径向刚度的影响。结果可作为HSK刀柄的应用和几何参数优化的指导。