计算机控制抛光中基于等面积增长螺旋线的加工路径

目前计算机控制抛光工艺中使用的阿基米德螺旋线路径,存在加工工件中心区域时工件转速过快的缺点.为了克服该缺点,分析了螺旋线路径加工的特点,分析表明工件的瞬时转速取决于加工点的驻留时间密度和螺旋线的面积增长速率.据此,提出了一种新的螺旋线作为抛光路径,该螺旋线的面积增长速率恒定,因此也称为等面积增长螺旋线.利用该螺旋线路径,加工转速趋于恒定,可降低加工中心区域的转速,从而降低对机床运动性能的要求,降低设备成本和加工成本.实验结果证实,阿基米德螺旋线路径加工中心区域容易产生过加工问题,加工精度较低;等面积增长螺旋线路径加工可避免中心区域过加工问题,获得较高的加工精度.

A Novel Path Used in Computer-controlled Polishing Process Based on Uniform-area-increment Spiral

Archimedes spiral path, which is widely used in computer-controlled polishing process, always brings about excessively high rotational speed, and consequently excessive machining when polishing central region of the work-piece. To resolve this problem, the characteristics of a universal spiral path are studied first. It shows that the instantaneous rotational speed of the work-piece depends on the local dwell-time density and the local increase rate of the area enclosed by the spiral. Based on this, a novel spiral was proposed as a polishing path. The increase rate of the area enclosed by this new spiral is constant, and therefore, it can be referred to as uniform-area-increment spiral. This spiral path can ensure the stableness of the rotational speed of the work-piece, and reduce the rotational speed in the central region. Consequently, it can reduce the demands on motion performance to machine, and reduce the cost for machine and process. Finally, experimental results verified that Archimedes spiral path causes excessive machining in the central region due to excessive demand for rotational speed, and results in lower precision, while the uniform-area-increment spiral path avoids the excessive machining in the central region and results in higher precision.