Cutting Process Consideration in Dynamic Models of Machine Tool Spindle Units

Reducing the deviation effect from the specified machining conditions on the quality of the process in real time is the desired result of the intelligent spindle control system. To implement such a control system, a dynamic interaction model of the technological machining system with the cutting process was developed. The transfer matrix method of a multibody system was used in the development of the dynamic model. The physical closure condition of the technological machining system for using the transient matrix method is implemented in the developed model by introducing into this model an additional elastic coupling of the contact between the tool and the machined workpiece. The model is presented as a dynamic model of the elastic system "spindle unit-workpiece/tool-cutting process-tool/workpiece". To develop the dynamic model, the system decomposition was performed with an analytical description of the joint deformation conditions of the subsystems and the use of the transient matrix method to calculate the harmonic influence coefficients of these subsystems. The proposed approach is used to calculate the native vibration frequencies of the spindle with the workpiece fixed in the chuck and supported with the tool. The calculation results correspond to the experimental ones and quite accurately represent their trends for different contact interaction conditions.