Simulation and Improvement of NC Programs for Machining Complex Surface

• Main Author: 蔡永霖
• Other Authors: 姚宏宗
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/15347255363276868803

碩士 === 國立中正大學 === 機械工程研究所 === 86 === 　　When generating NC codes, most CAD / CAM systems use tiny linear segments (Gol) to aproach the entire contour surface. When the requirement of part accuracy becomes higher, it may result in excessive size of NC. file. Due to the limitation of transfer speed, it usually takes longer machining time. The face angle of the machined surface also becomes extremely distinct. 　　To control the machining accuracy and the surface roughness of the machined part, we need to control the machine spindle speed and the machining feedrate. The rotational speed is relied on te design of a good spindle, while the feedrate can be controlled by a good NC program. However, most NC programs neglect the feedrate control problem. Therefore, it is often to see that NC programs pass the simulation test but fail in the real cutting situations. 　　In this thesis, we combine linear and circular machining methods to improve the machining efficiency. Not only are the NC codes reduced in size, but the transfer burden is also lessened. In addition, we develop an algorithm for automatic feedrate adjustment, which helps to optimize the feedrate while maintaining a required machining accuracy. Other than these, we also develop a simulation and verification system to verify the improved NC codes. The resulting system can effectively improve existing NC programs and therefore will be very useful for die and mold manufacturing industries to increase their productivity.