磨矿过程的多变量模糊监督控制

针对磨矿过程的关键工艺指标-磨矿粒度难以用现有控制方法进行有效控制的难题,提出一种由模糊监督器、磨矿控制回路预设定模型和磨矿粒度预报器组成的磨矿过程多变量模糊监督控制(MFSC)方法.MFSC方法用于对磨矿过程进行监督,根据工况变化对回路控制器设定值进行调整.通过控制回路跟踪调整后的设定值,可将磨矿粒度控制在期望目标范围内.工业试验表明了所提出方法的有效性.     

砂轮平衡精度的最小二乘测试计算法

提出一种测算砂轮不平衡精度的最小二乘新方法 ,给出基本原理和具体算法 .该方法能有效抑制测量误差的影响 ,大大提高测试精度 ;并能同时测出残余不平衡量的大小和相位 .可用于各类平衡器的精度测定     

Accurate robotic belt grinding of workpieces with complex geometries using relative calibration techniques

Robotic belt grinding operations are performed by mounting a workpiece to the end effector and commanding it to move along a trajectory while maintaining contact with the belt grinding wheel. A constant contact force throughout the grinding process is necessary to provide a smooth finish on the workpiece, but it is difficult to maintain this force due to a multitude of installation, manipulation, and calibration errors. The following describes a novel methodology for robotic belt grinding, which primarily focuses on system calibration and force control to improve grinding performance. The overall theory is described and experimental results of turbine blade grinding for each step of the methodology are shown.     

基于智能优化控制的磨矿过程综合自动化系统

本文首先概述了磨矿的工艺过程和控制要求,然后从系统结构与功能、智能优化控制策略等方面详细描述了磨矿过程综合自动化系统,最后谈到该系统的实施及应用效果。     

MODIFICATION OF GEOMETRY AND TECHNOLOGY OF CYLINDRICAL WORMS

The objective of this research is to develop a new method of grinding process that can efficiently make concave profile of the worm thread smooth. The grinding is carried out using a wheel with curvature profile in the axial plane in the form of an arc of logarithmic spiral. The proposed method will provide maximum line of contact between the tool and the worm with minimum stress concentration at any point. The generating equation of the grinding tool profile and its arrangement with respect to the worm during thread grinding were determined.     

Changes in the structure of hematite by extended dry grinding in relation to imposed stress energy

The effect of extended dry milling in different mills on the structural changes of hematite concentrate has been investigated using a combination analysis of XRD line broadening, BET and particle size measurements. Structural changes were followed by XRD line broadening analysis using integral breadth method and Warren-Averbach approach. For analysis, the stress energy was estimated by considering different grinding variables in different mills and changes in the structure discussed in terms of stress energy.Within comparable range of stress energy, lower BET surface area was produced by grinding in the vibratory mill. The maximum surface area increased to 18,400 m²/kg in the vibratory mill after releasing 51,300 kJ/kg energy. The conversion of the 80% of initial hematite to amorphous phase during extended dry grinding by tumbling, planetary and vibratory mills, needs 4000, 8500 and 50,000 kJ/kg energy respectively. It was understood that vibratory mill introduces the minimum lattice strain and gives the largest crystallites when applying the same level of stress energy. The smallest crystallites with grinding in tumbling, vibratory and planetary mills were obtained about 17.3, 13.5 and 5.6 nm after releasing 5230, 51,300 and 15,600 kJ/kg respectively. For these levels of stress energy, in turn, the microstrain <ε_L=10 nm²>^1/2 exceeds 4.4 × 10^− 3, 3.9 × 10^− 3 and 5.3 × 10^− 3.It was further revealed that higher concentrations of defects (Amorphization and excess energy) per unit surface area were induced by grinding in the planetary and tumbling mills. A theoretical calculation of the energy contribution to the long-lived defects indicated that products from tumbling and planetary mills have higher excess energy compared to the products from vibratory mill for the same stress energy. The maximum theoretical excess energy was estimated about 75.4, 80.0 and 81.3 kJ per mole of the ground hematite with tumbling, vibratory and planetary mills after releasing 5230, 51,300 and 15,600 kJ/kg of stress energy respectively. Grinding in vibratory mill needs much more energy to reach the same effect as the other used mills. A comparison of specific energy input and stress energy among the used mills points out that for generation of the same levels of stress energy, the planetary mill consumes more energy than the other used mills.     

转炉钢渣粉磨性能的实验研究

对转炉钢渣粉磨性能进行了实验研究。结果表明，钢渣的易磨性比熟料差，但优于矿渣。在钢渣所合矿物中，硅酸盐矿物易磨，含铁矿物难磨。通过粉后方式，可以将钢渣中具有胶凝活性的矿物选择性分离出来。     

45钢磨削硬化的试验研究

在平面磨床上,采用干磨削方式对45钢进行了磨削硬化处理,研究了磨削硬化层的组织与性能.结果表明,在磨削温度场和应变场的综合作用下,完全硬化区马氏体相呈现"细-粗-细"的变化规律,且相对粗大马氏体相出现在次表层;而过渡区组织的形成主要在于磨削热循环温度场的作用.磨削深度或原始组织对显微硬度无显著影响,硬度值均在700～750HV之间;但磨削硬化层深度随着磨削深度的增加或原始组织均匀性的提高,从0.9mm增大到1.4mm.     

表征PAN纤维和炭纤维微细结构的HRTEM样品制备方法

为用高分辨透射电子显微术(HRTEM)表征聚丙烯腈(PAN)纤维和炭纤维的微细结构，从纤维性能出发，探讨研碎、离子束减薄和超薄生物切片三种制备方法及其工艺步骤，结合实验结果，对比了三种制备方法的原理、优缺点，提出了制备方法的适用范围和选择原则，并推断适于表征预氧化纤维微细结构的样品制备方法。与生物样品的制备方法类似，把超薄生物切片法引入到纤维材料HRTEM样品制备领域，为系统研究炭纤维微细结构的演变提供了线索。     

V型钢导轨表面裂纹分析

对V型钢导轨在热处理后的磨削加工中出现的表面裂纹进行了宏、微观分析，硬度测试及热酸蚀试验。结果表明，磨削不当是导致V型钢导轨出现表面裂纹的主要原因。提出了改进措施。