Mechanism And Performance Research On C-X-Y Three-axes Coordinated Crankshaft Grinding

The engine crankshaft is one of the key parts, engine manufacturers have been working for accurate and efficient processing of the unremitting efforts of the crankshaft. As has always been more complicated geometry of the crankshaft, rigid relatively poor source of error when grinding very large, precision is not easy to guarantee. Thus, crankshaft grinding automobile engine manufacturing industry has been the difficulty and focus. Development from the traditional to the crankshaft machining CNC machining, crankshaft machining technology has been rapid development. Currently in crankshaft machining processing method is used mainly with the dynamic crankshaft grinding method C-X because of high precision CNC technology itself and this many times with the moving grinding to avoid positioning errors caused by clamping, so the high-precision machining a wide range of crankshaft Adopted this approach. However, in theory, with the moving crankshaft grinding C-X model, and there are inherent deficiencies in theory, cannot compensate for these deficiencies is to solve, so it is necessary to improve the model itself, to further improve the machining precision of the crankshaft. In the analysis of the C-X model itself after the discovery of the root causes of processing errors generated, this error can be increased through the Y direction of the wheel means freedom to be resolved, then established a new crankshaft with the moving grinding C-X-Y Mathematical model and theoretical verification. According to the basic principles of crankshaft grinding, grinding force on the wheel had some preliminary research, the basic parameters of grinding force in general need to experiment, according to the data summarized empirical formula. Crankshaft and wheel displacement, velocity and acceleration are the basic parameters of kinematics. These basic parameters in the calculation of the structure after the preliminary design of the grinder, and C-X-Y axis servo linkage crank grinder made some key parts of the corresponding technical requirements.First, reduce and avoid the error is an important task of precision machining. C-X-Y crankshaft axis in the establishment of linkage with the moving grinding motion model, the geometry of the grinding machine error analysis, concrete analysis of the crankshaft connecting rod grinding neck following error when the servo error in the first frame, wheel frame X-axis Y-axis error of Radius of processing, and processing the location of roundness deviation from the impact of the extent of the combined effects of C-X-Y axis error results. Also discussed the installation after the eccentric wheel, the wheel size changes, wheel wear on the machining accuracy and a number of laws related factors and treatment.Secondly, with the move for crank grinding mechanism of vibration analysis, concrete analysis of the root causes of vibration, because vibration forced vibration is the main factor error, it is necessary to carry out the function of the forced oscillation model. In the analysis of surface wave with the specific relationship between vibration, and found mainly due to forced vibration wheel imbalance, the imbalance in the final of the wheel vibration caused by in-depth analysis, the use of more freedom with the crankshaft vibration theory Activity grinding system reduced to four degrees of freedom vibration system and a mathematical model, based on modal analysis theory of equations were solved. A result of shock vibration crankshaft machining surface ripples. Forced vibration is not due to attenuation of vibration, need to pay attention to the dynamic balance and static balance wheel and avoid the natural frequency.