Research Of The Grinding Vibration Characteristics Of The CNC Gear Form Grinding Machine

Grinding is a machining process that refers to become the bank to workpices with certain size, shape, position accuracy and surface quality of the performance. The grinding process is complex. CNC forming grinding process will be accompanied by vibration, noise, grinding temperature, grinding burns and other phenomena. When the frequency of excitation force and the inherent frequency of Grinder parts are close or a multiple relationships, it can lead to higher modes of vibration or resonance. On the other hand, if the wheel axis of rotation is not balanced, it will make the surface of the gear chatter and the chatter may cause the regenerative effect, which can cause selfexcited vibration. Self-excited vibration makes the grinding process becomes unstable, it will seriously affect the degree of precision grinding machine, so vibration has a critical influence on the precision of gear grinding machine.This paper reviews the progress of the CNC gear form grinding machine and vibration theory. Then the workpiece-Wheel mathematical model is established in considering the main factors and ignoring the secondary factors, which analyzes the trends in the grinding force mathematical model under different process parameters First, by using multi-scale mathematical model analysis method, The amplitudefrequency characteristic curve equation of the primary resonance 、 harmonic resonance and sub-harmonic resonance are obtained, which provide a theoretical basis about the relationship between external excitation frequency and the natural frequency. Second, the use of the phase plane method to the mathematical model, using MATLAB simulation of the phase diagram of different angular frequencies and Poincare section diagram, and obtained that when angular frequency is from 29 Hz to 70 Hz range is the nonlinear vibration system resonant region, and will cause wear cutting system instability. Finally, the vibration test platform and the voltage test platform are established, By analyzing the collected test data, the correctness of the grinding force trends are verified and the relationship between grinding parameters, grinding force and vibrations are obtained, which providing a theoretical basis in optimizing CNC gear form grinding machine.Analyzing vibration test platform data got from the vibration test platform acquired the following conclusions: the local oscillator is mainly generated by the rotation of the spindle when the grinder in non-grinding state. Under the grinding state, the line speed is the main parameters that influence the grinding process. For different grinding process parameters all have a largest effect on the X-axis, Y-axis followed, Zaxis lest.Analyzing voltage test platform data got from the voltage test platform acquired the following conclusions: When the wheel speed becomes larger and larger, the grinding force decreases, resulting in a self-excited oscillation; when the workpiece feed rate becomes larger, the grinding force keeps constant, no self-excited vibration is caused due to insufficient amount of feed; when grinding depth becomes larger, the grinding force becomes larger, self-excited oscillation is not caused due to the occurrence of a low-speed stability grinding effect, by the above analysis of the data to verify the theoretical derivation of the grinding force trends, provided a theoretical basis for the accuracy of gear grinding machine in actual operation.