Abstract: For orthogonal turn-milling, as the cutting layer geometry of positive eccentricity was not considered, the overall change rules of cutting layer geometry were difficult to describe. To solve the above problems, formation processes of cutting layers were analyzed statically without consideration of kinetic influences based on motion law of orthogonal turn-milling. The mathematic models of cutting layer geometry of orthogonal turn-milling with positive eccentricity were set up and some mathematical expressions were gained such as entrance and exit angle, cutting thickness and cutting depth of side and bottom cutting edges. The above mathematic models were verified by experiments. Finally, some influences of cutting parameters on cutting layers of tool were researched. The above studies provide quantitative analyses for changes of cutting layer geometry on positive eccentricity orthogonal turn-milling and detailed theoretical guidelines for cutting forces and chatters.

Key words: positive eccentricity, orthogonal turn-milling, cutting layer geometry, mathematic model, side cutting edge, bottom cutting edge

摘要： 针对未考虑正偏心正交车铣切削层几何形状而导致难以全面反映正交车铣切削层几何形状变化规律的问题，基于正交车铣运动规律，在不考虑动力学影响的情况下，对切削层的形成过程进行了静态分析。建立的正偏心正交车铣切削层几何形状的解析模型涉及铣刀侧刃和底刃的切入/切出角度、切削厚度和切削深度。通过试验验证了该解析模型的正确性，并分析了切削参数对铣刀切削层的影响。研究结果为正偏心正交车铣切削层几何形状的变化提供了定量的分析依据，为切削力和颤振的研究提供了理论指导。

关键词: 正偏心, 正交车铣, 切削层几何形状, 解析模型, 侧刃, 底刃