棒材轧机辊缝调节液压马达装配结构改造

1问题的提出 棒材轧机辊缝调节液压马达型号为GMR125／620-H106。其将液压泵站输出压力转化为液压马达动力,带动蜗轮蜗杆传动进而调节轧机辊缝。运行过程中,液压马达的正反旋转通过液压泵站阀台中的三位四通电磁换向阀来实现控制。在应用过程中存在如下问题：     

首钢迁钢转炉滑板挡渣液压系统设计特点

对蓄能器、换向阀以及过滤器在滑板挡渣液压系统中的应用特点进行了分析。生产应用表明:正确使用蓄能器,既能节约能源,又能降低运行成本;按用途正确选用过滤器,可以最大限度的降低油液污染度,确保液压系统正常运行,提高系统的抗污染能力,降低运营成本;合理使用电磁换向阀,可以提高执行机构的反应速度。首钢股份公司迁安钢铁公司使用可快换式转炉滑板挡渣机构后,挡渣效果明显,挡渣的成功率达到100%。     

操作安全生产效率高的撬毛设备

瑞典霍尔姆海德设备公司研制的BrokkBM3000型橇毛机,系由一回转台与三节动臂组成。这种特殊装置可使锤头作1.1m范围的直线运动。台车为电动液压驱动,也可用柴油液压驱动。该台车一般可在预板高5m(最高7m)的矿山使用。     

全液压凿岩台车工作机构液压系统的改进

以ＰＬＵＴＯＮ－ １７ 型全液压凿岩台车为例, 分析了进口凿岩台车工作机构液压系统存在的缺陷及其对生产的影响, 对台车工作机构液压系统进行了改进, 增加了必要的液压元件,改善了台车工作机构的性能     

渣包车大臂举升速度下降的故障分析及排除

主要阐述了K350SH60型渣包车的基本构造,大臂举升液压控制系统的工作原理、介绍了大臂举升系统的故障现象、以及大臂举升速度下降的可能原因,并对液压系统的斜盘式变量泵、液压油缸、LS阀、平衡阀、主溢流阀与电液换向阀、大臂举升系统工作电路进行分析及排除故障的一些措施。     

梅钢高炉炉前自动化升级

梅钢五号高炉炉前原开口机、泥炮、移盖机采用液动控制系统,在阀站内扳动先导阀手柄完成炉前各项操作,作业方式落后,劳动效率低;在原液压系统的基础上进行改进,优化现场油管布置,更换液动控制换向阀为电液控制换向阀,配套安装电气及PLC控制系统,升级实现了炉前各项作业的遥控器操作,劳动效率得到提高,遥控系统为高炉出铁一键操作预留接口,提升了高炉设备的自动化控制水平。     

液控换向阀换向冲击在工程应用中的改进

液压换向阀的换向冲击是在液压系统工作中常见的一种现象,在实际工程应用中对设备的稳定影响较大。以消除液控换向阀换向冲击为出发点,分析了液控换向阀换向冲击产生的原因,并提出了工程应用中液控换向阀的改进方案,以达到降低换向冲击的目的。     

DL4型轮胎式采矿台车凿岩机控制系统的设计

轮胎式采矿台车在钻孔作业时,常因地质条件问题出现各种卡钎、断钎的现象。轻的一次浪费数根钎杆,严重的还会造成设备损坏,甚至是产生一些安全事故。因此,一套好的凿岩控制系统对采矿台车至关重要。本文对上述的问题进行了相关的研究,首先常规采矿台车的凿岩控制系统进行分析,然后对DL4型采矿台车的控制系统的设计思路进行了重点介绍。     

计算机辅助测试在电磁换向阀可靠性试验中的应用

计算机辅助测试（CAT）可以提高液压元件的测试精度、测试速度和测试的重复性．文章介绍了一种用计算机辅助测试方法对电磁换向阀的失效进行判断的方法，介绍了测试系统的硬件及其软件的开发，并指出了该测试系统的特点．     

6自由度气动摇摆台的控制研究

6自由度并联机构(DOF)具有刚度高,重量轻,输出力大等特点.一般这些并联机构都由液压或电机等方式驱动.本文介绍了6自由度气动摇摆台的结构、控制系统及其控制方法.     

高速铁路用钢轨生产技术

采用铌稀土(BNbRE)钢种,进行了钢的高纯净度、无缺陷连铸坯、高精度轧制、在线检验及相关技术研究,形成高级别钢轨生产工艺.结果表明:生产的钢轨能够满足<时速200公里客运专线60 kg/m钢轨暂行技术条件>的技术指标.     

关于高职教育终身化理念的思考

为了发挥高职院校在终身教育、终身学习、学习化社会的建设中的积极作用.对终身教育及高职教育终身化的理念进行了论述,提出了高职教育终身化的原则和构建终身教育及终身学习的体系.     

Guidelines for clinical use of drugs for involutional osteoporosis

Guidelines for clinical use of drugs for involutional osteoporosis will be released soon in Japan. Seven different types of drugs for osteoporosis are in market for clinical use in Japan. Those includes calcium, estrogens, anabolic steroids, calcitonins, active vitamin D3, ipriflavon, and etidronate. The guidelines recommend to clarify the risk factors in each patient before to start administration of drug. Patients with osteopenia are basically recommended to be followed without any drug treatment, but, patients with osteoporosis are generally recommended to be treated with drug after evaluation of risk factors. After menopause, inhibitors of bone resorption would be recommended as a first choice drug. For monitoring effects of treatment, bone mass measurement is so far the first choice, but bone metabolic markers would be used as well.     

Criteria for selection of patients for emergency portacaval shunt

A computer program analysis of the effect on survival of 74 preoperative factors was performed as part of a prosepctive study of the emergency portacaval shunt in 146 unselected patients with bleeding esophageal varices due to alcoholic cirrhosis. Only ascites, a serum glutamic oxalacetic transaminase level of 100 units or more, and a requirement for 5,000 ml or more of blood transfusion were associated with a statistically significant decrease in survival. However, none of these factors are contraindications to operation because their presence permits a survival rate of 37 to 40%. The only contraindication to emergency portacaval shunt is the combined presence of ascites, jaundice, encephalopathy, and severe muscle wasting, a constellation that was incompatible with survival beyond one year.     

The use of dimethylsulfoxide for fixation of yeasts for electron microscopy

Increasing numbers of young women with ovarian failure and women of advanced reproductive age (> 40 yrs) utilize oocyte donation to treat their infertility. In both groups, women who become pregnant frequently experience multiple gestation, occurring in up to 30% of pregnancies. Advanced maternal age and high-order multiple gestations are associated with an increased risk for obstetric complications. We reviewed the pregnancies of patients with high-order multiple gestations (> or = 3 gestational sacs) with respect to their antepartum course and neonatal outcomes. Mothers were divided into two groups according to age at conception; Group I (> or = 40 yr, n = 20) and Group II (< 40 yr, n = 10). These 30 high-order multiple gestations were found among 127 successful oocyte donation cycles (23.6% of all pregnant patients). Data regarding pregnancy outcomes were gained by chart review and telephone interview. Results demonstrated spontaneous reductions in the number of implantation sites were similar between groups (Group I: 21.4% vs. Group II: 17.6%). Multifetal pregnancy reduction (MFPR) was more often chosen by older women (Group I: 45% vs. Group II: 10%; P < 0.05). Antenatal complications were commonly experienced by both groups (> 80%) as were operative deliveries (> 85%). However, neonatal outcomes were generally good, with only one death occurring in the 79 delivered infants (1.3%). We conclude transferring supernumerary embryos to women undergoing ovum donation places patients at great risk for high-order multiple gestations. These pregnancies are associated with increased antenatal and neonatal complications. Although advanced maternal age is normally an added risk factor, well-screened older patients carrying high-order multiple gestations experienced similar outcomes as younger mothers.     

介绍一种生产冲挤用铝合金坯料的新工艺

哈兹列特铝板带连铸连轧工艺已被成功地用于铝和铝合金冲击挤压用坯料的生产。在对哈氏四个有关用户扫描的基础上，列举了其产品及其用途，并介绍了相关工艺及其优点。     

重轨孔型设计软件的编制

随着计算机在轧钢领域的广泛应用，重轨孔型设计利用计算机技术是今后发展的必然趋势，结合鞍钢大型厂的实际情况，编制了重轨孔型设计软件，应用该软件后，明显地提高了设计工作效率，加快了新产品的开发速度。介绍了该软件的编制方法、系统的功能及程序结构。