Study On Grinding Force Modeling Of Axial Ultrasonic Vibration Assisted Grinding

Abstract:It is called ultrasonic vibration assisted grinding (UVAG) when the ultrasonic vibration is added on the workpiece or the grinding wheel in the traditional grinding. It will produce impact, reciprocating ironing and ultrasonic lubrication effect in the process of UVAG which can reduce the grinding force, improve the quality of the workpiece surface, reducing the grinding heat and so on. To some extent, the UVAG can overcome some defects of the traditional grinding. The grinding force is an important parameter to evaluate the process and results of the grinding, so it is of significance to study the grinding force of UVAG and reveal the influence mechanisms and rules of the effect of ultrasonic vibration on grinding force. The grinding force of axial ultrasonic vibration assisted grinding (AUVAG) is researched based on the kinematics of grinding in this paper. The main research work of this paper include as the following:The movement equation of the particle in AUVAG was established according to the relative motion of the grinding wheel and the workpiece. The movement characteristics, trajectory of abrasive, arc length and the chip area were analyzed based on the movement equation. The results showed that the arc length of AUVAG is greater than the common grinding, while the chip section area is smaller than the common grinding.Assuming that the undeformed chip thickness submitted to the Rayleigh distribution, the average undeformed chip thickness calculation expressions of the ordinary grinding and the AUVAG are established. It found that the former is larger than the latter when analyzed and compared. Thus the useful conclusion that the formation force of AUVAG is smaller than the ordinary grinding has been obtained. And the reduction rate increases with the amplitude and frequency increasing, but the larger speed of grinding wheel will deduce the reduction rate. The friction on the main cutting direction of AUVAG is also analyzed based on the relation motion between the grain and workpiece. It is found that the friction of AUVAG is smaller than the traditional grinding, and the reduce degree is proportional to the amplitude and frequency. Based on the two parts of the formation force and the sliding force, the reason why the grinding force of AUVAG is less than ordinary grinding force was analyzed. And the grinding force models under two kinds of grinding method are obtained.The grinding forces are investigated in different grinding depth, table speed and amplitude of ultrasonic vibration based on the experimental study. The results indicated that the grinding forces increase with the increase of grinding depth and table speed. But at the same grinding parameters, compared to the ordinary grinding, the grinding force of AUVAG decreased to some extent. In addition, with the increase of amplitude, the reducing rate of grinding force increases. The grinding force models are verified by the experimental data and the result showed that they are effective. Chart41, Table9, Bibliography73.