横向翻边模设计

1.问题的提出 板料已有内孔的翻边是一种常见的冲压加工工艺,通常采用先冲孔再用翻边模具进行翻边加工的工艺过程,而翻边模的设计有其常规的设计方法。但有些特殊异形零件的翻边模,如果采用常规     

轿车后背门内板冲压工艺及模具设计

轿车后背门内板是轿车车身中典型的零件。根据零件冲压工艺性,设计了工件成形的5个工序,分别为:落料-拉深成形-修边冲孔-修边冲孔-翻边修边整形冲孔。根据工艺设计内容,利用UG和AutoCAD软件,设计了后背门内板冲压成形的五套模具。根据设计的模具尺寸进行加工制造,通过模具的实验预压得到轿车后背门内板的冲压零件。根据零件是否合格验证工序的合理性和模具设计的可靠性。     

钼片冲孔翻边工艺的改进

冲孔翻边工艺在生产中应用广泛,其特点是零件加工工序少,降低了工时消耗和材料消耗,对形位公差要求严格的零件更为适用。传统的钼片冲孔翻边工艺早已形成,如电子管中的管芯件有几种就是通过冲孔翻边加工而成的,但真正满足设计文件要求的零件较少,大多数零件均为翻边开裂的不合格产品。在装配应用时,只能作为不合格品利用,     

拉深、翻边、切边和冲底孔复合模具设计

根据零件的结构特点及技术要求,围绕如何降低生产成本、提高工作效率和简化模具结构,通过比较多种工艺方案,采用线切割进行剪料,以定位板进行定位,确定了由拉深、翻边、切边和冲底孔等工序组成的冲压工艺方案,并对其所有工序进行了工艺计算;同时,设计了1副拉深、翻边、切边和冲底孔复合模具。结果表明,采用此工艺方案和模具结构显著提高了盒形零件的生产效率和产品质量。     

汽车消声器连结法兰零件翻孔模的设计

本文以汽车消声器连结法兰为研究对象,分析了其冲压工艺,设计了其加工工艺方案。并对翻孔工艺进行了工艺计算和设计翻孔模具,阐述了模具工作过程和设计要点。经生产实践验证,本案研究的方法和采用的方案解决了翻边开裂的技术问题,从而提高了产品合格率。     

U形罩冲孔翻孔复合模具设计难点

U形罩为我公司的常用零件,材料为无氧铜,料厚1mm,采用冲压加工。其冲压工艺为：落料引深一冲孔一翻孔。由于该类零件产量很大,为了提高生产效率,我们对其加工工艺进行分析,尝试设计冲孔翻孔复合模具,将冲孔、翻孔两道工序一次加工完成。图1、图2为常规工艺的冲孔、翻孔工艺图。     

新型孔翻边模具的设计

针对制作汽车控制臂衬套装配孔的新工艺技术需求,设计了一种新型的圆孔翻边模具.新型模具结构紧凑,布局合理.利用楔形增力机构压边,采用弹性模具材料制作一带开口的凹模来实现退料.它较好地解决了空间受限情形下的模具退料问题及因压边力不足而造成的金属流动问题.新模具的开发应用可以为外形复杂,空间结构布局受限的零件翻边工艺提供解决...     

YB电机通风槽板槽孔模具设计

主要介绍YB电机通风槽板槽孔的模具设计,该零件的槽型工艺为落料→冲孔→翻边三部分来完成,本文着重阐述通风槽孔翻边模具的工作原理、模具结构及主要工作部件的设计和参数计算.对于我公司小批量生产,此模具结构简单,设计巧妙,成功地解决了异形孔翻边的问题,大大降低了模具成本及生产周期.     

框架类零件在制造过程中的误差分析

重点介绍了传动机构关键零件框架的整体工艺方案和重点工序（精加工）的制造精度分析,全面分析了该类零件的结构特点并制定了制造工艺方案,同时对重点工序-基准精密加工和行星轮轴孔的精密加工工序进行了分析,找出了装配误差、基准定位误差、找正误差、图样标注方法等影响零件制造精度的因素,并针对主要矛盾制定了有效的解决途径,消除不必要的影响因素保证零件的设计精度。     

一种踏板冲压成型工艺及模具设计

介绍了某工程车辆扶梯踏板的结构,通过设计冲孔落料复合模和翻孔翻边复合模优化踏板加工工艺,保证了踏板的成形质量,提高了零件的生产效率,将模具成型踏板经过实际生产验证,批量实施于企业产品中,提高了企业的经济效益。     

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.