线切割机床的编程及使用技术讲座：第四讲 编程技巧

一、间隙补偿的特殊部位及其处理 1.程序中的附加程序 线切割加工时,电极丝首先停在基点上(通称入丝点或零点),然后用一道程序将电极丝的轨迹引到工件轨迹线的起点,这道程序称为引入程序。将工件割完后,又用一道程序将电极丝以终点(往往就是起点)引回到基准点,这道程序称为引出程序。引入程序与引出程序往往是形式相同而方向相反的两条直线程序。有时,还需把电极丝从一个基准点引向另一个基准点(俗称“跳步”),这种程序称为过流程序。     

基于ISO14649标准的STEP-NC程序生成器

为实现STEP-NC程序的自动生成,开发了STEP-NC程序生成器.首先阐述了程序生成器的工作原理和各个模块的功能及其实现方法.详细论述了程序生成器实现中的三项关键技术.最后,结合一个包含平面、孔和型腔特征的AP203文件,利用所开发的程序生成器生成符合ISO14649标准的完整的STEP-NC程序,并通过STEP-NC铣削仿真系统对所生成的程序进行切削仿真.仿真结果表明,所开发的STEP-NC程序生成器是可行的.     

数控加工中工件程序原点的设置与偏移

程序原点的建立关系到坐标点的计算和加工程序的编制,因此要对工件程序原点进行合适的选择.本文对工件程序原点的设置,特别是多坐标程序原点的偏移提出了几种方法.     

FANUC 0i 18i 21i系统通用PMC程序在数控立式加工中心的应用

一、编制通用PMC程序的一般思路 1．通用PMC程序的应用目的 编制通用PMC程序,主要应实现以下目的：①程序尽量包含本类机床具有的所有功能。     

基于VERICUT软件对程序切削参数的优化

通过对数控程序的VERICUT仿真,介绍了使用VERICUT软件对数控程序进给速度参数的优化,以及优化后数控程序的比较与分析,最终得出加工效率较高的数控程序。     

拨码开关选择加工程序的设计

研究了拨码开关选择加工程序的硬件和PLC的设计方法,实现了拨码开关选择加工程序,并自动运行选择的加工程序,简化了启动加工程序的流程。     

发那科五轴加工中心任意轴旋转测量程序的开发

介绍了发那科五轴加工中心任意轴旋转测量程序的原理和编制方法,对测量程序参数进行了定义,并给出了补偿原理、程序流程图和注意事项。这一测量程序具有较高的实用价值。     

浅谈全程序空白对环境监测结果的影响

通过对监测全程序空白采样吸收管封口与不封口以及实验室分析全程序空白的对比试验 ,探讨了全程序空白测定方法对环境空气质量监测的影响。认为环境空气质量监测 ,现场采样时应对监测全程序空白采样吸收管封口作处理 ,才能充分体现监测全程序空白的真实性 ,以满足质量控制的要求     

结合标准算例说明SAP5程序的使用

SAP程序是分析线性结构系统静力和动力问题的通用有限元计算程序。我国自去年引进SAP程序以来,应用SAP程序,解决了一机部产品结构分析的一些老大难问题。在SAP程序的调试和推广使用中,我们发现由于对国外程序系统的结构,卡片输入方式等不太习惯,或因对SAP程序使用不熟悉,常常容易出错。因此本文的目的在于结合标准算例说明SAP程序的使用以及计算结果的分析,以便于读者更好地掌握程序的应用,便于SAP程序的推广。     

VC和FORTRAN混合编程及其在微机电系统中的应用

对VC和FORTRAN混合编程中的函数传递问题,进行了深入的研究,研究出了一种从VC程序到FORTRAN程序的函数传递技术.运用这一技术实现了从VC程序向FORTRAN优化设计程序传递优化模型,进行优化计算,为FORTRAN优化程序的可视化提供了一种解决途径.实例说明技术的应用价值.     

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.     

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.