Abstract:

The crankshaft is a so important part of the automotive engine that the machining accuracy of Ballig of its main journals and crankpins in grinding process has a great impact on the engine performance. The profile of the form grinding wheel reflects on the crankshaft journal in plunge grinding process directly. Therefore, a method for on-line measurement and compensation of the profile of the form grinding wheel is proposed based on the cutting depth model, which ensures the accuracy of Ballig of crankshaft journals in grinding by controlling the profile accuracy of grinding wheel in dressing process. Based on the monitoring system using the acoustic emission sensor, the basic mathematical model of the relationship between the RMS of acoustic emission signal and the cutting depth in grinding wheel dressing is established. To improve the accuracy and reliability of the basic model, the cutting depth model with the variable parameters is introduced by constructing the function between the model parameters and the dressing parameters, such as the feed rate and the mid-drum. And then a method for the compensation of the profile of grinding wheel and its implementation process in dressing process are put forward. The experimental results show that the actual dressing profile of the grinding wheel for evaluating its profile error quantitatively can be achieved by the cutting depth model and thus the machining accuracy of Ballig of crankshaft journals can be satisfied by compensating for the profile error of grinding wheel in dressing.

Key words: acoustic emission signal, cutting depth model, parameters identification, wheel dressing, ballig grinding