润滑油对变速箱传动效率影响的试验研究

变速箱是汽车传动系统中重要组成之一,研究如何提高变速箱传动效率具有重要意义。润滑油影响变速箱使用性能,从而影响整车性能及油耗,其中润滑油的黏度是润滑油的重要理化指标之一。通过配制新的润滑油,分别研究试验油和参比油对变速箱传动效率台架试验及整车滑行油耗试验的影响情况。结果表明:黏度相对较低的润滑油对于提高变速箱传动效率及降低整车油耗有着重要意义,低粘化是变速箱油改善的方向之一。且在变速箱效率提1%时,综合油耗提升0.2L/100Km。     

前置前驱车型传动系阻力的分析与优化

汽车传动系的性能影响整车油耗,为了降低传动系阻力,减小油耗,在四驱五电机台架上对某前置前驱车型传动系进行了阻力的试验探究。试验探究表明,该车型阻力与挡位、发动机转速均呈正相关;该车型传动系中阻力最大的部件是变速箱。对影响变速箱功率损失的润滑油进行了效率试验,对比变速箱在4种不同润滑油条件下的效率,优选出润滑油2#,通过试验得出它较原厂油的综合效率提高了0.43%。     

NEDC工况下润滑油对整车油耗的影响研究

在NEDC工况下,通过试验比较目标车在相同实验条件下使用不同润滑油的市区、郊区和综合油耗,分析润滑油性能对整车油耗的影响。试验结果表明：整个NEDC工况下,发动机油温在25~100 ℃之间,其中市区工况下在25~80 ℃之间,郊区工况下在80~100 ℃之间;使用低黏度润滑油可以有效降低油耗,但是黏度过低会增加郊区工况的燃油消耗;添加黏指改进剂和摩擦改进剂均能有效地降低油耗。      

NEDC工况下润滑油对整车油耗的影响

在NEDC工况下,通过试验比较目标车在相同实验条件下使用不同润滑油的市区、郊区和综合油耗,分析润滑油性能对整车油耗的影响。试验结果表明:整个NEDC工况下,发动机油温在25~100℃之间,其中市区工况下在25~80℃之间,郊区工况下在80~100℃之间;使用低黏度润滑油可以有效降低油耗,但是黏度过低会增加郊区工况的燃油消耗;添加黏指改进剂和摩擦改进剂均能有效地降低油耗。     

润滑油对NEDC工况变速器传动效率的影响分析

变速器作为传动系关键的零部件之一,直接影响整车的NEDC油耗。为了提升某MPV车型的NEDC综合油耗,提出了一种基于NEDC工况的变速器效率测试方法,并利用该方法对比了不同润滑油的黏度、温度、添加剂等因素对变速箱传动效率的影响。试验表明,该测试方法能更准确地反映变速器NEDC工况下的综合效率;润滑油黏度相对越低,变速器的传动效率越高;油温升高引起的油膜厚度的减少对变速器效率的影响大于因转速升高引起的油膜厚度的增加对变速器效率的影响,且有利于提高变速器的传动效率;润滑油增黏剂有利于提升油品的黏温特性,且在一定温度范围内,随着温度的升高,润滑油黏温特性对于变速器传动效率的影响大于润滑油黏度对变速器传动效率的影响。     

润滑油黏度对后桥传动效率和整车油耗影响的试验研究

随着国家政策鼓励和油价的逐步攀升,降低汽车的油耗受到广泛的关注。汽车的油耗和传动效率密切相关,后桥在汽车的传动系统中起着重要的作用,而不同的润滑油对后桥的传动效率有着很大的影响。结合润滑油的黏度与齿轮啮合损失及搅油损失的相关研究进行了分析,根据相关的试验验证,得出黏度相对较低的润滑油对于提高后桥传动效率,降低整车油耗有着重要意义。     

低黏度变速器油对整车油耗和变速器可靠性的影响

从燃油经济性和可靠性两方面分析低黏度变速器油对手动变速器的影响。燃油经济性通过变速器传动效率台架试验及整车NEDC循环试验进行评价,试验证明低黏度变速器油可以降低1. 3%的整车油耗;通过对变速器疲劳寿命试验和温升试验进行评价,确定了低黏度变速器油对变速器可靠性的影响。     

涡轮增压发动机用0W-20润滑油减摩性能研究

为研究低黏度润滑油对涡轮增压发动机燃油经济性的影响,配制5种不同的0W-20全配方润滑油。使用真实活塞环-缸套摩擦副试样,选取涡轮增压发动机关键工况,通过往复摩擦模拟试验测试各油样的减摩效果。通过控制整车WLTC油耗测试精度,比较各油样的燃油经济性提升效果。结果表明：降低润滑油黏度和添加摩擦改进剂均可以改善燃油经济性,但是后者的效果更为显著;摩擦改进剂MoDTC的加剂量越高,减摩效果越好;硼酸盐清净剂可以增强MoDTC的减摩效果。比较摩擦模拟试验和整车油耗试验发现,使用真实的环套摩擦副组件并设定合适工况的摩擦模拟试验,可以快速区分润滑油的减摩效果,但是无法反映真实的燃油经济性的提升程度。     

润滑油对变速箱传动效率影响的实验探究

汽车传动系统效率的优劣直接影响整车油耗,传动系统中变速箱的传动效率是很重要的一环,通过研究对比不同种类的润滑油及润滑油添加剂对传动系统的影响,对汽车润滑油的选用提供一种参考方案。实验表明,添加黏指剂能改善油品的黏温特性,传动效率的高低,与润滑油的黏度指数相关;转速越高,传动效率越高,但当转速过高,效率反而出现下降,是由于搅油功率损失所占比率超过润滑油对传动系统效率的贡献率。     

低黏度GF-60W-16发动机油节能摩擦模拟试验

为了进一步提高汽车燃料经济性,ILSAC颁布的节能发动机油规格已发展到黏度更低的GF-6级别。由于GF-6发动机节能台架试验周期长、成本高,为了提高开发GF-6 0W-16汽油机油配方的筛选效率,利用摩擦模拟试验分析0W-16汽油机油的摩擦润滑性能,并采用综合分析法研究摩擦模拟试验结果和发动机节能台架结果的相关性。结果表明：汽油机油配方中各添加剂之间的协同效应对其节油率和摩擦润滑性能产生显著影响,有机钼添加剂含量多的低黏度GF-6 0W-16汽油机油比参比油GF-5 0W-20更具减摩作用;试验温度激发汽油机油中有机钼减摩剂进一步发挥作用,降低摩擦因数;所建立的摩擦模拟试验综合分析法能够较好地预测低黏度GF-6润滑油节能台架试验结果。     

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.     

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.     

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....     

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.