而且能实现对工件不同加工区域定位误差有针对性的重点防控。实验结果表明:使用该方法计算得到的工件最大定位误差小于0.2 mm
远远优于传统均布支承/定位点在相同实验条件下实验件0.8 mm的最大定位误差
从而抑制了工件外形定位误差对加工质量的扰动。提出的支承/定位点初始布局方案可为进一步的全局优化
并以此控制工件加工变形、提高工艺系统刚度
最终改善加工质量奠定基础。
Abstract
To restrain the dynamic change of effective locators in the manufacturing process of large thin-walled components
a new “X-2-1” locating method is proposed to distribute the location/support points following machining region
with the goal to meet the requirements for the clamping force
positioning accuracy and maximum support capacity. This method can ensure reliable clamping in the machining process of workpieces
and control positioning error in different machining regions. Simulation and experiment show that the maximum positioning error is 0.2 mm
much better than that obtained when twenty location/support points are distributed evenly over the whole support area of a workpiece. The improvement suppresses the perturbations of clamping deformation to machining quality. Furthermore
the optimization result of initial distribution of location/support points provides a foundation for a further global optimization of multi-point location distribution of large thin-walled components so as to increase process system's stiffness
decrease machining distortion
and improve machining quality.
关键词
Keywords
references
CAI W, HU S J, YUAN J. Deformable sheet metal fixturing: principles, algorithms, and simulations [J]. Journal of Manufacturing Science and Engineering, 1996, 118(3): 318-324.
HU Fuwen, LI Dongsheng, LI Xiaoqiang, et al. Locating simulation for aircraft skins NC trimming based on flexible holding fixture [J]. Computer Integrated Manufacturing Systems, 2012, 18(5): 993-998.
HU Fuwen, LI Dongsheng, LI Xiaoqiang, et al. Process planning of aircraft skins NC trimming based on reconfigurable fixture [J]. Journal of Beijing University of Aeronautics and Astronautics, 2012, 38(5): 675-680.
KING L S, HUTTER I. Theoretical approach for generating optimal fixturing locations for prismatic workparts in automated assembly [J]. Journal of Manufacturing Systems, 1993, 12(5): 409-416.
DEMETER E C. Min-max load model for optimizing machine fixture performance [J]. Journal of Engineering for Industry, 1995, 117(2): 183-186.
MENASSA R J, DEVRIES W R. Optimization methods applied to selecting support positions in fixture design [J]. Journal of Engineering for Industry, 1991, 113(4): 412-418.
PONG P C, BARTON R R, COHEN P H. Optimum fixture design [C]∥Proceedings of the 2nd Industrial Engineering Research Conference. Los Angeles, CA, USA: IIE, 1993: 6-10.
DEMETER E C. Fast support layout optimization [J]. International Journal of Machine Tools and Manufacture, 1998, 38(10/11): 1221-1239.
LIU Chunqing, HONG Jun, WANG Shaofeng, et al. Searching optimization algorithm for deformation control of aircraft thin-walled parts in multi-point flexible tooling system [J]. Journal of Shanghai Jiaotong University, 2013, 47(8): 1191-1197.