厢式压滤机滤布自动冲洗机构设计改进与对比分析

介绍了厢式压滤机常用的几种自动冲洗滤布装置的结构、存在的问题及相应的改进。     

腈纶压滤机液压系统的技术改造

针对腈纶压滤机保压效果差、能耗高及漏胶严重等问题,对其原有液压系统进行了技术改造。设计出定位准确、保压效果好的节能型液压系统;为减少油液泄漏而污染环境,设计出双层结构的封闭式油箱。结合可编程控制器(PLC)实现了压滤机的安全和方便操作。     

U型棚＋围岩注浆技术在巷道修复中的应用实践

在对新集三矿原软岩巷道支护及修复方案存在问题的基础上,提出了巷道排水疏干后适时采用U型棚＋围岩注浆加固的巷道修复支护方案,工程应用实践表明：采用该支护方案后围岩变形较小（稳定）,达到了预期的目的。     

Effect on Particle Size to Emitted X-Ray Intensity in Pellet Cement Sample Analyzed with WDXRF Spectrometer

Abstract

The particle size and heterogeneity effects on the analyte line were investigated for the analysis of powdered samples by X-ray fluorescence technique. In the analysis of samples utilizing the powder method, these effects caused serious errors with variations in particle size for the emitted intensity. The fluorescence intensities of some elements in pellet samples of cement (the range of particle sizes, < 32 µm, 32–38 µm, 38–45 µm, 45–63 µm, 45–75 µm, 75–106 µm, and 106–150 µm and, at press pressure 3.50 and 1.41 × 10⁷ kg/m²), are measured using a wavelength dispersive X-ray fluorescence (WDXRF) spectrometer for 14 pellets prepared according to the powder method. The results show that the K _α X-ray fluorescence intensities from samples can effect about 17% maximum differences in normalized intensities within selected particle sizes. These experimental results were interpreted by comparing with the other experimental results in the literature.     

压接式IEGT芯片布局对其温升的影响

压接式电子注入增强型门极晶体管PP-IEGT(press pack-injection enhanced gate transistor)封装内采用多芯片并联结构,芯片间的布局对器件温升与稳定性有着重要影响。在现有的对齐阵列布局下,芯片间严重的热耦合效应会导致器件结温较高,因此提出一种交错阵列的圆形布局。基于有限元热稳态仿真分析,对比了2种布局下的芯片温度分布,以及封装内各层组件的温度差异;同时,考虑不同功率损耗和外部散热条件的影响,对2种布局下各层组件温度变化进行了讨论。结果表明,提出的交错阵列布局可有效改善热耦合效应,芯片上的热量得到更好地耗散。此外,各芯片和器件整体的温度分布均匀性得到了提高,为更大电流参数PP-IEGT的芯片布局设计和稳定工作提供了参考。     

不同围压条件下钢纤维混凝土受压试验研究

对不同钢纤维体积率的混凝土复合材料在不同围压条件下进行受压试验。针对钢纤雏混凝土在三向应力状态下的强度、变形行为的复杂性,基于试验数据和拟合公式,得出了不同围压和不同钢纤维体积率对钢纤维混凝土峰值强度和应变的影响系数,建立了其峰值应力比、峰值应变比与围压比的关系模型。分析计算结果显示,该模型可以有效的描述不同围压下钢纤维混凝土的力学性能．     

高速压力机组合机身优化设计

利用ANSYS软件对高速压力机组合机身进行优化设计。根据组合机身的特点建立了优化模型;利用灵敏度分析确定对目标函数和状态变量影响较大的设计变量,提高优化效率;提出7个优化方案并进行优化计算。优化设计后,改善了高速压力机机身的动态特性,减小了机身质量,达到预期效果。     

Integrated Manufacturing System for Precision Press Tooling

The press tooling industry, characterised by many small-scale job-shops, is facing an increasingly competitive global market. This comes at a time when there is a shortage of experienced process planners and unavailability of affordable CAD/CAM systems that could provide an integrated solution for manufacturing sheet metal tooling. Many commercially available CAD/CAM systems are either too expensive or too narrow in scope, in the sense that they provide only point solutions. The design of press tools and its manufacturing functions are highly specialised and knowledge-intensive in nature. This paper presents a framework and the implementation details of an integrated system that has been developed for a local sheet metal tooling company specialising in precision punches and dies. A PC-based system has been implemented on an AutoCAD platform using the Autolisp programming language.     

粘介质成形工艺特点与应用分析

简要介绍了近来出现的利用粘性介质传压进行冲压成形的一种新工艺。通过粘介质成形实验与以水为介质的液压成形模拟的对比分析,得出了ＶＰＦ过程中的一些工艺特点,并分析了ＶＰＦ工艺在飞行器制造中的应用前景。     

采用工艺强化措施提高S195型柴油机曲轴的疲劳强度

讨论Ｓ１９５型柴油机曲轴强度的薄弱环节－过渡圆角弯曲疲劳强度。介绍了几种工艺强化措施可大幅度提高疲劳强度,建议新设计的曲轴取较小的过渡圆角,使整机结构要紧凑。