The trend in die/mold manufacturing at present is towards the hard machining at high speed to replace the electron dis- charge machining. Failure forms of the AlTiN-coated micro-grain carbide endmill when used for th...The trend in die/mold manufacturing at present is towards the hard machining at high speed to replace the electron dis- charge machining. Failure forms of the AlTiN-coated micro-grain carbide endmill when used for the machining of JIS SKD61 (HRC 53), a widely used material in die/mold manufacturing, are investigated. The endmill shows a characteristic that tool life decreases greatly due to the chipping when overload occurs or the rapid increase of wear when over-heat accumulation in cutting edges. As a consequence of the investigation, a strategy to regulate heat generation in the end milling process is proposed. This is accomplished by controlling the cutting arc length, i.e. the length of each flute engaging workpiece in a cutting cycle. Case studies on the slot end milling and comer rounding are conducted. The results show that the proposed strategy suggests the optimal tool path as well as the optimal pitch between successive tool paths under the cutting time criterion.展开更多
本文基于EPICS控制架构,研制一套4 MV单端静电高压型离子加速器高压端控制系统。系统硬件以PLC为基础,应用模拟量、数字量高压隔离模块配合浪涌吸收保护电路的设计方法,提高了系统稳定性,解决了高压端放电对控制系统的损坏问题。基于上...本文基于EPICS控制架构,研制一套4 MV单端静电高压型离子加速器高压端控制系统。系统硬件以PLC为基础,应用模拟量、数字量高压隔离模块配合浪涌吸收保护电路的设计方法,提高了系统稳定性,解决了高压端放电对控制系统的损坏问题。基于上位机软件CSS开发了友好的操作界面,实现了对所有被控对象的有效控制。采用STEP7下位机软件开发了独立的高压端PLC程序,在保障被控设备有序运行的同时,可实现通讯中断后的可控停机,防止被控对象失控。应用Linux系统构建实验物理及工业控制系统输入输出控制器(Experimental Physics and Industrial Control System Input/Output Controller,EPICS IOC),完成过程变量(Process Variable,PV)的发布,实现上下位机数据的交互。经测试,该系统工作稳定,抗干扰能力强,可为单端高压型离子加速器高压端控制系统研制提供参考。展开更多
文摘The trend in die/mold manufacturing at present is towards the hard machining at high speed to replace the electron dis- charge machining. Failure forms of the AlTiN-coated micro-grain carbide endmill when used for the machining of JIS SKD61 (HRC 53), a widely used material in die/mold manufacturing, are investigated. The endmill shows a characteristic that tool life decreases greatly due to the chipping when overload occurs or the rapid increase of wear when over-heat accumulation in cutting edges. As a consequence of the investigation, a strategy to regulate heat generation in the end milling process is proposed. This is accomplished by controlling the cutting arc length, i.e. the length of each flute engaging workpiece in a cutting cycle. Case studies on the slot end milling and comer rounding are conducted. The results show that the proposed strategy suggests the optimal tool path as well as the optimal pitch between successive tool paths under the cutting time criterion.
文摘本文基于EPICS控制架构,研制一套4 MV单端静电高压型离子加速器高压端控制系统。系统硬件以PLC为基础,应用模拟量、数字量高压隔离模块配合浪涌吸收保护电路的设计方法,提高了系统稳定性,解决了高压端放电对控制系统的损坏问题。基于上位机软件CSS开发了友好的操作界面,实现了对所有被控对象的有效控制。采用STEP7下位机软件开发了独立的高压端PLC程序,在保障被控设备有序运行的同时,可实现通讯中断后的可控停机,防止被控对象失控。应用Linux系统构建实验物理及工业控制系统输入输出控制器(Experimental Physics and Industrial Control System Input/Output Controller,EPICS IOC),完成过程变量(Process Variable,PV)的发布,实现上下位机数据的交互。经测试,该系统工作稳定,抗干扰能力强,可为单端高压型离子加速器高压端控制系统研制提供参考。
