Force prediction model of high efficiency U pass milling

U pass milling is an efficient rough method that combines the characteristics of flank milling with traditional cycloid milling. This cutting method has the characteristic of smooth cutting force and can meet the requirements of large-depth processing parameters. Cutting force is an important basis for optimizing processing parameters and designing machine tools, cutting tools and fixtures. In this paper, a U pass milling force prediction model considering variable cutting thickness and multi-edge cutting is established. The U pass milling characterization parameters are defined. The tool path is discretized into multiple micro-element trajectories, and a numerical algorithm of instantaneous U pass milling cutting thickness partitioned by trajectory intersection points is proposed. By discretizing the cutting edge curve, the contact criterion of the cutting edge micro-element is established, and the length of instantaneous cutting edge contact area is calculated by searching along the edge curve. According to the distribution state of the upper and lower boundaries of the cutting edge, different forms of multi-edge cutting discrimination methods are proposed. By equal proportion partition of cutting layer, the analytical equation of cutting force coefficient is established, and the coefficient distribution form of variable cutting thickness is obtained. Combined with the micro-element cutting force, the U pass milling force prediction model is obtained by the basis transformation. The milling test result shows that the predicted value is consistent with the measured value of amplitude and trend, which proves the effectiveness of the prediction model in the U pass milling.