液压元件检测系统研究与设计

液压元件的质量是液压系统可靠工作的核心基础,因此对液压元件进行性能检测,对于减少后期设备故障,并为故障分析提供相关依据具有重要意义。拟定了检测系统的整体测试原理方案,液压元件检测系统公称压力为32MPa,测试压力为32MPa,公称流量为160L/min。对该试验台各个组件进行了选型和装配设计,包括各个集成块单元组件的装配设计,最终完成了液压元件检测试验装置中各个集成块、泵站及检测台台架、被试阀阀板等系统检测单元的总体装配设计。在具体方案实施中采用了二维设计与三维设计相结合的方式,以二维设计为主,三维模拟设计为辅,完成了对液压元件检测装置的结构设计。     

装载机液压系统试验台组成及技术要求

装载机液压系统整机性能台架试验,是将装载机元件的台架试验与机载试验进行整合,在实验室内实现装载机整机液压系统(包括泵、阀、缸、油箱、管路和接头等)动载模拟试验。其主要目的是检测整个液压系统的性能参数,可优化和筛选最佳的装载机液压系统方案,研究和验证装载机液压系统的内在性能,为装载机液压系统的开发和改进提供科学准确的试验依据。     

液压元件的测试

各种液压元件,特别是泵、马达、液压缸、阀在制造或修理完了时,都要进行测试,目的是了解液压元件的质量,保证产品寿命,这是非常重要的一环。在液压元件中最主要的元件还是液压泵与液压马达。而它们的测试中最主要的项目又是应用各种液压试验台进行压力、流量、扭矩和转速的测试,快速高效准确地检测各种液压元件的参数大小和性能特征,达到区分液压元件质量好坏,寿命长短。进而判断液压元件可否正常稳定的使用。     

如何使用数控车床加工液压阀体上的圆锥内螺纹

液压阀是构成液压系统的重要元件之一,为了便于加工制作或与液压系统其他元件联接,它的阀体上常常加工有起密封作用的圆锥内螺纹,这些圆锥内螺纹的加工精度直接影响液压阀产品的性能和质量。     

机械多体动力学与液压系统联合仿真

建立机械系统与液压系统之间相互作用的模型,对机械液压系统进行了联合仿真.利用ADAMS液压系统模块建立液压系统回路的框图,然后将其连接到机械系统模型中,选取求解器分析整个系统的性能.得到了系统机械部件和液压元件的性能曲线.对ADAMS液压模块使用中需要注意的一些问题作了介绍.     

双级换向阀组合的逻辑回路

液压系统工作性能的优劣与液压元件性能和质量及液压系统的结构有关。用双级换向阀组合的逻辑回路,所用元件的品种和数量以及外接管路数少,系统的结构简单紧凑,且能逻辑组合出多种滑阀机能。     

超高压液压元件试验台计算机辅助测试系统

以VC 6.0为基本工具,采用面向对象的原理和技术,建立了超高压液压元件试验台的计算机辅助测试系统.在选择高性能的硬件和设计稳定可靠的测控软件基础上,实现了液压元件最高压力70 MPa的性能检测的要求.试验表明系统稳定、可靠、安全和经济.     

掘进机液压元件检测、冲洗多功能装置的研发

为了进一步提高掘进机质量、降低液压系统故障率,需设计一种可用于泵、阀、马达、油缸等液压元件检测、冲洗多功能装置。一方面,可以准确检测、掌握各液压元件的实际参数;另一方面,可以作为车间的液压元件冲洗设备使用。本文中提出了掘进机液压元件检测、冲洗多功能装置的主要技术指标,通过理论计算,确定了该装置的泵、阀、马达、油箱的参数,为下一步的选型、采购工作打下了基础。     

液压系统的组成

一个完整的液压系统由五个部分组成,即动力元件、执行元件、控制元件、辅助元件和液压油。动力元件的作用是将原动机的机械能转换成液体的压力能,指液压系统中的液压泵,它向整个液压系统提供动力。     

叉车用多功能液压试验台

液压系统是内燃平衡重式叉车的重要组成部分,液压系统性能的好坏,液压元件质量的优劣,将直接影响叉车整机的性能。据有关资料统计,在整机故障中,叉车液     

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.     

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。     

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....     

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.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.