夹具定位原理在机械产品设计中的应用

夹具是机械产品设计的重要工艺设备,种类多、功能丰富。结合使用需求合理设计夹具,能降低操作人员的劳动强度,提高机械产品设计与加工效率。因此,加强夹具定位原理在机械产品设计中的应用尤为重要。文章简述了机械加工定位基准和夹具设计原理,明确机械加工夹具效用及设计标准、定位分类和定位方案,重点探讨了机械产品设计中夹具定位原理的应用和发展趋势,为研究机械产品设计提供理论参考。     

基于KBE的组合机床夹具快速设计系统的研究与开发

为提高组合机床夹具的设计质量和效率,将KBE技术应用到组合机床夹具的设计流程中。在对组合机床夹具的结构特点和功能进行分析的基础上,提出了基于KBE的组合机床夹具快速设计系统的设计方案。利用NX/Open二次开发技术以及基于VS.NET集成开发环境开发出了组合机床夹具的快速设计系统原型,该系统通过开放的形式支持设计人员修改设计方案,实现设计人员与计算机之间的交互式协同设计。最后以柴油机缸体加工用夹具为例,验证了基于KBE的组合机床夹具快速设计系统的能够有效地重用设计知识,保证了夹具产品设计质量,提高了夹具产品设计的效率。     

基于零件特征的生产工艺系统的研究

结合一个ＣＡＤ／ＣＡＭ一体化工程的实例,分析基于产品零件特征的生产工艺系统的总体结构,讨论其中３个子系统的关键技术,介绍了一种基于产品零件特征的集成模式,并开发基于产品零件特征的ＣＡＰＰ系统和ＣＡＦＤ系统,该系统提出了工艺过程和夹具的半智能化设计的模式,利用特征技术将ＣＡＰＰ的设计过程前镶后嵌于ＣＡＤ与ＣＡＭ中,实现产品设计与工艺设计过程的并行和夹具设计的半自动化。     

基于制造环境约束的并行设计方法研究

并行工程强调集成地、并行地设计产品有其相关过程，为ＣＩＭＳ的总体优化提供了新的思路和技术，本文首先分析并行设计的实质及实施并行设计的方法和关键技术，然后从面向制造的设计及制造环境以产品设计的约束来研究并行设计方法。通过开发制造环境建模工具，建立制造环境能力库，实现产品设计可制造性评价的信息反馈，从而实现并行设计。     

并行设计技术在顶套式剃齿夹具研制中的应用

介绍了并行设计技术的具体实施过程,评价了并行设计技术的应用效果,并引入并行设计思想,对剃齿夹具的功能、结构、工艺性、可靠性进行了研究,设计出的新型顶套式剃齿夹具不仅有很高的定位精度,而且在刚性、寿命、可靠性方面均优于现行的各类剃齿夹具.     

产品并行设计技术研究

本文提出了基于集成产品信息模型，实现产品并行设计的体系结构。在产品设计过程中采用分阶段策略，基于知识对产品设计进行评价，及时指导产品设计，从而优化产品及其设计过程。     

基于Pro/E的机床夹具虚拟装配的研究

主要采用自顶向下的虚拟装配方法,以Pro/E软件作为开发平台,研究夹具的虚拟装配方法,对进入装配的零件进行虚拟设计和分析,以期及时发现夹具设计中的问题,缩短产品设计与制造周期,为夹具设计开辟一条新的设计途径。     

面向产品并行设计的敏捷夹具设计系统

敏捷夹具是具有“敏捷”特性的夹具。根据产品并行设计对夹具设计系统的功能需求,提出敏捷夹具设计系统由基于Web的敏捷夹具辅助设计工具和夹具CAD组成。论述了敏捷夹具设计系统的总体结构、设计流程、网络环境和敏捷夹具设计系统等关键技术,最后介绍了敏捷夹具辅助设计工具的实例HT－AFDT。     

绿色产品并行闭环设计方法

分析了传统设计方法的不足，提出了基于并行工程思想的闭环产品设计方法，并给出了并行闭环产品设计的系统框架，指出根据此方法可设计出人－机－环境友好的绿色产品。     

产品并行设计的多目标模糊决策

在描述并行设计多目标模糊关系的基础上，提出一种产品设计的多目标模糊决策模型。作用应用，研究了某型号自动步枪并行设计的多目标模糊决策。     

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.