铁路客车底架牵引梁改进及加工工艺

通过工艺分析与研究,改进了铁路客车底架牵引梁的结构,选取了优质材料,优化了制造方法,降低了成本,提高了工作效率,产品精度有了很大提高,同时提高了车辆的承载能力,延长了使用寿命,现已广泛用于国内及出口车辆的制造,并获得了国家发明专利.     

我们正在改变

带着盛夏的酷热,2005年第7期《机械工程师》又和您见面了。细心的读者早就发现,今年的《机械工程师》厚了,重了,载文量多了,信息量大了,内容丰富了,编排新颖了,印制精美了……总之,无论是内在质量还是装帧设计,都有了很大的改变。的确,《机械工程师》正在改变,而改变最大的,还是编者自己。我们删除了气馁,恢复了自信,建立了目标;我们下载了责任,发送了决心,预定了成功。我们,朝着办精品期刊的奋斗目标,笔耕在每一期杂志的字里行间。我们,带着中国制造走向世界的理想,行进在中国机械工程师的队列里。我们勤奋敬业,秉守编德,我们踏实认真,团队…     

飞刀式纸护角裁切机构的设计

设计了一种飞刀式纸护角裁切机构,利用了曲柄滑块的运动原理,提高了裁切速度,缩短了纸护角最小长度.飞刀式纸护角裁切机构省去了现有护角机上的液压装置,减少了动力源的数量,减轻了整机的重量,在降低成本的同时提高了生产效率,并获得了更广的纸护角长度加工范围.     

立车横梁装配工艺改进

重点介绍了立车横梁装配工艺的改进,通过对传统工艺的改进达到了快速高效的装配,提高了机床装配精度,缩短了生产周期,降低了工人的劳动强度,降低了生产成本,提高了生产效率,从而为企业带来更大的经济效益。     

液压系统的改造设计研究

对冷床上卸钢系统和四辊轧机开卷机液压系统存在的问题进行了分析,找出了产生问题的原因,并对原液压系统进行了改造,经改造后的系统,减少了油液的泄漏,提高了系统的稳定性,减小了维修强度,降低了维修成本,提高了系统的工作效率.     

富气压缩机密封改造

论述了富气压缩机轴封系统改造。分析了原轴封系统存在的问题,提出了改造方案,进行了技术经济分析。通过将原浮环密封改造为千气密封,成功地解决了原轴封暴露的缺点,延长了轴封使用寿命,提高了可靠性,减少了运行成本,实现了零选出,方便了整套系统的维护,实现高自动化控制。     

曲轴锻档试验总结

本试验总结是针对我厂长期以来在生产中所发生的曲轴内部质量关键问题,我们进行了一些试验研究工作,到目前为止已取得了初步成效。在1964年内由于我们抓了三结合,过去三次试验均失败了的4L-20/8曲轴-单拐曲轴的（金叚）造压档第一次获得了成功,并稳定地贯彻在生产中,取得了较好的经济效果,保证了（金叚）件内部质量,节约了钢材和工时,降低了曲轴的制造成本,特别是开创了我厂单拐曲轴的压档新工艺,破除了迷信,树立了敢想敢干的革命精神,大大地鼓舞了进行新技术试验的信心,并且相应地丰富了我们的技术研究工作。正是在这个精神鼓舞下,工人们又进行了冲档的试验亦获得了成     

直线伺服自寻优前馈补偿方法

分析了一类变凸椭圆车床直线伺服系统的主要特点,提出了基于相位和幅值补偿前馈方法,基于连续系统分析了该方法原理的可行性;为适应量产控制系统的差异,采用了自寻优方案,提出了微分降阶方法,简化了参数辨识计算。设计了基于离散系统的CAR模型参数辨识算法,并进行了MATLAB仿真验证,之后在Dspace1104系统中进行了实验验证,获得了满意的效果。     

模数铣刀代用的计算机辅助设计

给出了模数铣刀的设计和代用计算的全过程,计算结果表明,该方法不仅提高了工作效率,缩短了设计周期,而且减少了工装,降低了生产成本,提高了生产效率。     

高速铣削机床电主轴综合监测系统研制

介绍了高速铣削机床电主轴的使用现状,分析了影响电主轴工作效率的各种因素,总结了电主轴综合监测系统的功能需求,设计了相应的硬件系统,给出了硬件结构框图及主要模块的设计电路.根据硬件系统,阐述了下位机控制软件的结构及工作原理,设计了软件流程图,分析了上位机监测软件的功能,给出了上位机监测软件的工作界面.     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.