铰杆——斜楔式气动夹具增力机构设计及力学分析

设计了一种气动夹具增力机构,是利用典型的铰杆和斜楔增力模块组合成铰杆-斜楔式串联传动机构,通过角度效应,实现力的三级放大.介绍了该机构的组成及工作原理,按照力学模型推导出了增力系数和输出力的计算公式,分析了各工作参数对增力效果的影响.该机构具有结构简单、紧凑、增力系数大等优点,同时可利用单一输入力,实现气动夹具对工件进行双侧对称夹紧的过程.     

钢球-双锥面二次增力气动夹具

介绍了基于钢球-双锥面式二次增力气动夹具的工作原理和力学计算公式。利用钢球一双锥面二次增力机构,不仅能实现力的同向输入输出,而且可在结构紧凑的前提下,对输入力进行高倍放大后输出。     

基于气动肌腱与二次正交铰杆增力机构的夹具系统

简述了气动肌腱作为一种新型的柔性气动执行元件,具有许多普通气缸所不具备的特性,能较好地适应制造技术绿色化发展趋势,将气动肌腱与各种形式的机械增力机构相结合,是一种实用而又新颖的创新设计方法。在此基础上,介绍了两种以气动肌腱为驱动力的二次正交铰杆增力气动夹具的结构特点、工作原理,并给出了其力学计算式。     

气动肌腱驱动的二次型铰链增力机构

介绍了一种利用气动肌腱与铰链机构相结合实现两次增力的新型夹具的结构特点、工作原理，推出了其理论与实际增力系数的计算公式，并分析了其优点。     

高倍增力机构在内孔夹具中的创新与研究

本文设计了两种适于内孔直径较大工件的、基于正交增力机构的离心式内孔夹具,结构中采用了互相垂直的输出重块与增力重块,通过斜楔增力机构或铰杆增力机构进行力的传递,使得该夹具相对于同样结构重量但没有增力机构的离心式内孔夹具,实际输出力的数值要大得多,输出转矩的能力也要大的多。     

一种新型的钢球增力液压夹具

介绍了一种新型的钢球增力液(气)夹具，推出了其理论增力系数和实际增力系数的计算公式，并对它与其他两种钢球增力液压夹具的性能进行了比较。     

基于气动肌腱与杠杆-双面斜楔增力机构的高效夹具

介绍了一种以气动肌腱为驱动,利用杠杆-双面斜楔机构进行增力的高效夹具。该夹具的装卸时间与加工时间重合,高效节能,绿色环保。     

钢球增力液压夹具

介绍了双钢球和三钢球增力机构与无杆液压缸组成的液压夹具系统,给出了其输出力和增力系数的计算公式。钢球增力机构与无杆液压缸组成的液压夹具,具有结构简单紧凑、制造工艺简便等优点     

钢球增力液压夹具的力学计算

介绍了两种应用于液(气)夹其中的钢球增力机构,推出了其理论增力系数和实际增力系数的计算公式,并对它们进行了性能比较.钢球增力机构与无杆液压缸组合而成的夹具,具有力传递效率高,结构简单,制造工艺简便的优点。     

基于斜楔增力的离心式内孔夹具

介绍了利用斜楔增力的离心式内孔夹具的工作原理与力学计算公式。基于斜楔增力的离心式内孔夹具结构简单紧凑,能使夹具产生较大的驱动转矩。     

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.