喷涂用气浮轴承涡轮动力学分析与结构创新设计

高速旋杯喷涂系统是汽车涂装生产线上的关键设备,其中喷涂用涡轮则是涂料雾化的核心动力。重点论述喷涂用涡轮的结构特点,分析气浮轴承的动力学特性,阐述气浮轴承涡轮的结构创新设计。样机测试结果表明,该创新结构设计合理、可靠、实用,能够满足喷涂工艺要求。     

一类气浮支承高速喷漆涡轮运动稳定性和轴心轨迹的研究

建立了一类气浮支承高速喷漆涡轮非线性动力学模型。基于数值分析理论，在宽转速范围内分析了气浮支承喷漆涡轮系统的运动稳定性和动态响应，研究了在工作和非工作状态等参数点处的时间历程曲线、相图和轴心轨迹图，得出了系统发生霍普夫(Hopf)分岔的临界值范围及轴心轨迹随轴承轴颈间隙的变化规律。     

基于多目标优化的汽车混合流水线平衡方法研究

近年来混合流水线逐渐被国内外汽车生产企业所接受并使用。由于流水线中混合了不同工艺的产品,如何将混合流水线调整至最大效率是其广泛深入汽车制造行业的主要障碍。目前对于混合流水线平衡系统的研究多为独立优化,分析了混合流水线平衡系统的组成部分:流水线平衡部分以及流水线排产部分的相互合作关系,提出对平衡系统整体求解的要求,指出使用具有协同求解各子问题能力的合作性协同进化算法求解这一多目标优化问题。     

汽车涡轮增压器产线中取气管压入工位的研究

涡轮增压技术已经非常普及,随着汽车行业的快速发展,汽车涡轮增压器技术也得到了快速的推广。汽车涡轮增压器经常处于高速、高温下工作,其生产工艺要求非常高。本文主要针对某汽车涡轮增压器自动化生产线中的取气管压入工位做了研究,详细介绍了此工位的工作流程及主要部件的功能。     

涡轮增压器壳体铸造工艺分析与改进

创新改变生活,基于人们生活质量不断改善、对物质要求越来越高的大背景下,人们对于代步工具的汽车需求量只增不减,为了更好的响应国家节能减排的环保号召,减少汽车废气排放量的涡轮增压器引起了越来越多研究学者的注意,有必要对影响涡轮增压器质量关键因素的压壳工艺进行探究,以保障涡轮增压器的制作质量,加快促进涡轮增压器在汽车中更加普及应用。     

探究汽车发动机涡轮增压器原理及常见故障处理

如今的汽车已经成为人们日常出行的重要代步工具,而且随着人们生活水平的提高,对于汽车各方面性能的水平要求也逐渐提升。汽车发动机涡轮增压器能够显著提高汽车的动力,并为用户带来更为良好的驾驶和出行体验。但在汽车发动机涡轮增压器的实际使用中,一些常见故障就会直接影响到汽车的正常价是甚至于驾驶人员的人身安全。本文在简单叙述汽车发动机涡轮增压器结构组成及其运行原理的前提下,就其常见故障处理以及使用过程中的注意事项进行了深入探讨。     

小型高速精密气浮气动主轴的研制

针对微结构的超精密磨削要求,设计了一种涡轮驱动的小型气浮主轴。采用了涡轮叶片作为动力结构部分,由压力气体驱动,带动主轴高速旋转;同时也采用了空气静压轴承作为支撑;建立了气动涡轮的设计模型,分析了气体静压支承轴承的结构参数,仿真研究了各设计参数对轴承承载力的影响,得出了最佳的设计尺寸和主轴工作参数,对涡轮与转轴组成的整体转子进行了模态分析,计算出了主轴的临界转速,研究了主轴的加工工艺。试验结果表明:该设计合理,达到了设计要求。     

汽车发动机陶瓷涡轮完成道路试验

燃气轮机发动机采用陶瓷涡轮盘是瑞典伏尔伏(VOLVO)公司所属的马尔摩联合透平公司首创,最近已完成了一次汽车道路试验。该汽车的燃气轮机发动机采用了陶瓷涡轮。燃气轮机要在汽车发动机方面与活塞式发动机竞争,必须在热效率上超过后者,这就有必要探索一种涡轮材料,其耐高温性能优于现在的金属涡轮。陶瓷材料是一种耐高温的理想材料,但是汽车用燃气轮机的涡轮转速高达每分钟5～10万转,在这样高的转速下,一般陶瓷材料经受不住因离心力所产生的应力。     

人机界面在CV9汽车车体焊接流水线中的应用

以重庆长安的CV9汽车车体焊接流水线为背景,论述人机界面MP370结合S7-300PLC在汽车车体焊接流水线中的应用,提出了设计原理和软件设计方案,并简要讨论了系统的通信组态及基于Windows面板的几种下载方法.     

汽车废气涡轮增压系统浅谈

随着科技的发展,废气涡轮增压技术在汽车发动机上的应用越来越广泛,在能源危机越来越严重的今天,废气涡轮增压技术合理的利用尾气能量,在不增加能耗的前提下,有效的提高了内燃机的能源利用率。本文针对汽车废气涡轮增压技术的原理和结构进行论述,并就废气涡轮增压技术的发展趋势进行浅要分析。     

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.