展开轮的反求设计与特征参数方程的建立

The Unfolding Wheel Reverse Design and the Establishment of the Characteristic Parameter Equation

展开轮是钢球表面缺陷自动检测设备中的关键部件,直接影响检测精度,目前只能从国外购买.针对以上问题,首先基于逆向工程技术,运用光栅扫描仪对展开轮进行数字化扫描,提出在数字化模型的基础上,运用样条曲线与自由曲面特征相结合的建模方法,对展开轮进行准确的逆向建模,并给出准确的模型;其次根据模型,提取了展开轮部分结构参数及工作部位曲面的截面特征参数.最后运用Matlab软件,对提取的截面点云进行曲线拟合,得到了工作部位曲面的线性方程.结果表明此方法的运用有助于实现展开轮的精确建模,进而为实现展开轮的加工奠定了基础.

Unfolding wheels are critical equipment in steel ball surface defect detector, which affects the detection precision directly. Currently, unfolding wheel can only be fetched through importing. To address the problem, this paper applies reverse engineering techniques on modeling of unfolding wheel. First, a three-dimension raster scanner is used to perform a digital scanning on the unfolding wheel, resulting in an ＇initial digital model. Then, a hybrid modeling method using spline and freeform surface feature is proposed based on the digital model. Next, part structure parameters and the characteristic parameters for working surface of the unfolding wheel are extracted ac- cording to model of unfolding wheel. Finally, curve fitting is performed on the section point cloud using MatLab, the working surface linear equation is obtained. The result shows that the efficacy of the high-accuracy modeling method proposed in this paper, which serves as a theoretical base for machining the unfolding wheel.