Digital copy milling—autonomous milling process control without an NC program

Conventional NC machine tools do not generally allow the change of cutting conditions such as depth of cut and stepover during machining operations, once they are given machining commands as NC programs. For that reason, the NC programs must be prepared adequately and verified in advance, which requires extensive time and effort. It is therefore necessary to develop functions to generate the cutter path autonomously and control the cutting conditions adaptively during machining to optimize the cutting process, maintain stable cutting, and avoid cutting trouble. This paper proposes a new architecture to realize autonomous control of the cutting process without using NC programs. A technique called digital copy milling is developed to control the NC machine tool in real time. The digital copy milling system can generate tool paths in real time, based on the principle of copy milling. In addition, a new control strategy is developed to control the cutting conditions adaptively. A prototype of an autonomous controller was implemented in a three-axis control machining center. Thereafter, experimental milling tests were carried out to verify the effectiveness of the proposed system. The cutter paths were generated autonomously by the digital copy milling system. Results show that the cutting depth and stepover can be changed during milling tests. Cutting conditions were controlled adaptively.     

基于回归法的钛合金(Ti-6Al-4V)插铣铣削力建模分析

针对钛合金(Ti-6Al-4V)的切削特点,研究了具有高速、高效特点的Ti-6Al-4V的插铣过程,分析了切削力的特点,构建了切削力分析试验平台,对铣削力的变化规律进行了研究,采用Taguchi正交试验法,运用多元线性回归法进行数值拟合,建立Ti-6Al-4V插铣过程铣削力模型．经试验验证,该模型是有效的,铣削力误差在10%以内,为研究钛合金插铣过程提供了依据．     

宏程序在垫块零件铣削加工中的应用

宏程序是通过循环语句和变量的控制实现规则曲面的加工,它具有修改方便,易读性好,程序段短等优点,在实际生产中占有一席之地。垫块零件是企业中急需的备件,采用合理的宏程序对垫块零件进行加工,可以提高加工效率,也可以为相关技术人员提供参考。     

The critical condition for intrusion of a steel ball into sliding contact space

The intrusion tests of a ball into sliding contact space were carried out. A stainless steel ball with 3.175 mm radius was used as a sphere particle to study the critical intrusion condition of the ball into the contact space between the organic glass and the polyurethane rubber. The effect of intrusion angle of the contact space and the friction coefficients among the ball, the organic glass and the polyurethane rubber on the critical condition were studied experimentally. Then, the intrusion conditions for the ball into the contact space were analysed theoretically. The results showed that the calculated critical intrusion angles agreed well with the experimental ones. Finally, the intrusion diagram as a function of critical intrusion angle, friction coefficient µ₁ and µ₂ (here, µ₁ is the friction coefficient between the ball and the polyurethane rubber, µ₂ is the friction coefficient between the ball and the organic glass) was introduced to evaluate the intrusion performance of a ball into the sliding contact space. Copyright © 2010 John Wiley & Sons, Ltd.     

高速切削金刚石立铣刀的动态特性研究

采用有限元分析方法,研究了三种不同结构的立铣刀高速旋转时的等效应力和位移大小及分布情况。系统地分析了刀具转速和悬伸长度对立铣刀径向位移、最大等效应力的影响规律。分析结果可以为高速切削金刚石立铣刀的设计提供可靠的理论依据。     

平面铣削中铣刀状态监控现状的评述

对平面铣削的特点和切削力进行评述,采用一齿周期内的合力平均值(准平均合力),以及力的一次差分方法。评述了刀具破损和磨损的评定指标和评定方法。描述了各种数据处理的方法,特别对人工神经网络的方法进行了描述。     

铲齿铣刀刃磨后对螺旋槽加工精度的影响分析

螺旋槽多采用铲齿成型铣刀加工,刀具沿前刀面刃磨后刃形不变,但其直径将减小,使计算出的铣刀廓形发生变化,其加工的螺旋面端面廓形将产生误差。给出可求出工件端面的截形坐标计算式和实际加工的工件螺旋面方程式,可推算出工件截形与螺旋面的加工误差。     

滚珠丝杆副磨合力矩检测控制系统的开发

介绍了测试实验台的结构组成及其工作原理,阐述了检测控制系统的硬件配置和软件的设计编写及其检测控制功能,讨论了电气比例阀的应用,并对系统的实际运用进行分析。     

淬硬钢Cr12高速铣削力实验研究

对淬硬钢Cr12进行了高速铣削实验研究,研究了铣削速度、背吃刀量、进给速度对铣削力的影响。研究表明:铣削力随着铣削速度的增加而减小,当铣削速度增加到一定的值后其下降趋势变得平缓;铣削力随背吃刀量的增大而增大,且变化显著;铣削力随进给速度的增加而增加,但增加不大。