考虑耕犁的超声磨削表面微观形貌建模与预测

Modeling and Predicting Surface Topography of the Ultrasonic Assisted Grinding Process Considering Ploughing Action

超声磨削加工在难加工材料领域得到广泛应用,超声辅助磨削过程中,超声振动参数对磨削后的表面微观形貌具有重要影响,因此,为了在加工前对超声加工后的表面微观形貌进行预测,以优化加工参数。提出一种考虑耕犁的超声磨削表面微观形貌建模与预测方法。假设磨粒为球形,磨粒直径与间距服从高斯分布,给出砂轮形貌的数值生成方法;根据超声磨削运动学,建立考虑磨粒实时切削深度与耕犁影响的三维运动轨迹方程;在此基础上,提出超声磨削表面微观形貌生成的区域逼近求解算法,进而给出超声磨削表面微观形貌生成模型,模拟出超声磨削的三维表面微观形貌。通过试验分别从表面微观形貌的轨迹纹理、表面粗糙度数值两个方面对超声磨削表面微观形貌的模型的正确性进行了验证。

Ultrasonic assisted grinding is widely used in the field of difficult-to-machine materials. During ultrasonic assisted grinding, the ultrasonic vibration parameters have a major impact on ground surface. Thus, in order to optimize machine parameters before grinding according to simulation results. A new method to model and predict surface topography of the ultrasonic assisted grinding process considering ploughing is proposed. A grinding wheel surface model considering the random distribution of grain is established by supposing the grits are spherical. Based on the geometric mapping relationship between grains and workpiece in ultrasonic assisted grinding, the cutting model of grains considering the real-time cutting depth and ploughing action is presented. The regional approximation calculation method is provided afterward. Consequently, the three-dimensional surface topography of ultrasonic assisted grinding is simulated. At last, this model is verified by the experiment through the surface texture and surface roughness parameters.