空间圆柱凸轮轮廓曲面的计算机生成方法

提出了模拟圆柱凸轮加工过程的圆柱凸轮轮廓曲面的计算机精确生成方法:建立刀具中心空间轨迹方程,保持刀具矩形截面垂直于刀具中心轨迹且沿其切线方向运动,从而在空间圆柱上切割出凸轮轮廓曲面。使用Pro/ENGINEER编程时,则将刀具中心空间轨迹方程程序化为基准曲线,应用可变截面扫描工具使矩形截面垂直于基准曲线且沿其切线方向运动,即可在圆柱实体上切割出该圆柱凸轮轮廓曲面。实现了直动从动件圆柱凸轮轮廓曲面设计的可视化和参数化。

基于Pro/E野火版的蜗杆三维参数化造型程序设计

以Pro/E野火版为开发平台,以蜗杆为研究对象,利用关系式约束的可变截面扫描和切削方法创建蜗杆实体。并以Pro/pro-gram模块为开发工具,进行蜗杆的三维参数化造型程序设计,用户根据人机交互界面的提示,输入相关参数,即可自动生成蜗杆的三维实体,从而缩短产品的开发周期,提高设计效率。

有理曲面的截面设计方法

本文在分析张量积有理B样条蒙皮面曲面方法不足的基础上,给出了用截面外形设计原理构造有理蒙皮曲面、回转曲面及扫掠曲面的方法,并提出了对G^1连续的有理曲线进行重新参数化使其达到C^1连续的方法。文中的实例表明用该方法能够产生满足设计要求的参数曲面。

A Particle-in-cell scheme of the RFQ in the SSC-Linac

A 52 MHz Radio Frequency Quadrupole （RFQ） linear accelerator （linac） is designed to serve as an initial structure for the SSC-Linac system （injector into Separated Sector Cyclotron）.The designed injection and output energy are 3.5 keV/u and 143 keV/u,respectively.The beam dynamics in this RFQ have been studied using a three-dimensional Particle-In-Cell （PIC） code BEAMPATH.Simulation results show that this RFQ structure is characterized by stable values of beam transmission effciency （at least 95%） for both zerocurrent mode and the space charge dominated regime.The beam accelerated in the RFQ has good quality in both transverse and longitudinal directions,and could easily be accepted by Drift Tube Linac （DTL）.The effect of the vane error and that of the space charge on the beam parameters have been studied as well to define the engineering tolerance for RFQ vane machining and alignment.