Railway equipment in general . tolerancing of metal pieces . permissbiles deviations of dimensions with non tolerance indication . allowance for machining 铁路通用设备.金属零部件的公差.未标明公差的尺寸的允许偏差.机加工余量
Railway equipment in general . tolerancing of pieces . usuals grad of precision realizable according to the manufacturing processes . allowance for machining 铁路通用设备.零部件公差.根据制造工艺可实现的精度的普通等级.机加工余量
It was showed that it is not necessary to use fixture at the early stage of machining , hut appropriate admittance must he set aside 结果表明，在粗加工阶段，可以不采用工装，但必须留出合适的加工余量，余量的多少可以通过节点最大位移来估算。
When they program they often set conventional cutting parameters for some things , such as machining remains , material ' s asymmetry and tools " wear cannot be premeditated , which will be blighted to the quality of the machining workpieces 在编程中往往无法预先考虑实际加工过程中出现的一些情况如：加工余量的不一致、工件材质的不均匀、刀具的磨损等对加工质量的不良影响，将加工参数设置得较为保守。
The generation of the tool path means that by the geometrical models of parts , according to the adopted machines , the tools , the cutting patterns , the cutting allowance and etc . , under some principles , the calculation of the cutter location was done and the tool path was generated 刀具轨迹的生成是指通过零件几何模型，根据所选用的加工机床、刀具、走刀方式以及加工余量等，按照一定的导动规则进行刀位计算并生成加工运动轨迹。
Firstly , tool - path for rough machining is generated through setting cutting depth , machining allowance and other parameters . interferences are resolved through raising the z - components of the generated cl point according different kind of situations . and then two methods to generate tool - path for finish machining is presented 首先通过设定切削深度和加工余量等参数生成递归分割曲面模型的粗加工刀具轨迹,对刀具轨迹生成过程中多种抬刀情况分别进行处理,避免粗加工中的过切干涉。
An optimizing arithmetic for calculating the best - fit sphere is also proposed , the result shows better accuracy is reached comparing to " three points method " , from 107 . 8umrms to 25 . 66umrms . during interferometric optics test with null lens , " nonlinear errors " of the testing coordinates will be introduced . a method based on ray - tracing , nonlinear fitting and coordinate transferring is proposed to eliminate these errors 在ccos控制模型及理论计算方面，提出了一种适用于高次离轴非球面最接近球面计算的优化算法，经计算，某矩形离轴非球面最接近球面半径的求解精度较传统的“三点法”有了较大的提高，理论加工余量由原来的107 . 8umrms降低到25 . 66umrms ；提出一种基于磨头与工件的相对位移量的控制模型，并且开发了阻尼卷积迭代算法，引入“虚拟加工”的概念进行迭代求解和参数评价。
Abstract : technology dimensions of work parts always exceed the determined technology dimension limits . but when the work parts are big enough , it is still possible and valuable to modify the work parts " following technology process and technology dimensions , which are respectively called as dynamic technology process ( dtp ) and dynamic technology dimension ( dtd ) , to ensure them to be qualified . a mathematical model is proposed which is about how to plan the dtd once the dtp is determined . a software has been written to testify the correctness of the above model . this model will be very useful in the capp and online quality assurance in the manufacturing of precise machine parts 文摘:工件的工艺尺寸在工艺过程中经常会超出许可的范围，但当这些超差工件仍有足够的加工余量时，通过修改其后续工艺路线(称为动态工艺路线)及工艺尺寸(称为动态工艺尺寸)仍有可能将其加工成成品.本文提出了一种在后续工艺路线确定后如何确定后续工艺尺寸的数学模型，并利用该模型成功地编制出了动态工艺尺寸设计的软件，且用很多事例验证了该模型的正确性.该方法可以应用于精密机械零件制造时的计算机辅助工艺过程设计及在线质量保证
