刀具半径补偿在铣削加工中的过切研究

采用数控铣削的方式对零件的轮廓进行加工时,受刀具半径补偿建立方式的影响,在尖角过渡的型腔加工中常存在不同程度的过切问题。采用不同的刀具半径补偿建立方式,对比其在尖角过渡处产生的过切问题,根据零件偏置路径在尖角过渡点的曲线分布特征,运用矢量分析法详细总结了合理利用刀具半径补偿功能避免过切的加工控制方法。     

数控铣削加工刀具干涉现象的剖析

介绍了数控铣床上刀具半径补偿的目的、建立与取消的方法,对刀具半径补偿中产生的过切现象、干涉现象及解决方法通过实例进行了详细的阐述与分析,并对建立刀具半径补偿过程中的注意事项进行了实践总结。     

数控铣削加工中的刀具半径补偿过切现象分析

零件轮廓数控铣削手工编程时,通常采用刀具半径补偿的方法。按照工件轮廓编程,通过改变刀具半径补偿值来控制零件加工尺寸,实现同一程序、同一刀具进行同一零件轮廓的粗、精加工。但在应用刀具半径补偿编程加工中,时常会出现过切或过切报警,需要正确分析和处理才能正确使用刀具半径补偿。文中将过切现象分为3类：与切入切出路径有关的过切现象、与刀具半径补偿值大小有关的过切现象和与刀具移动量有关的过切现象,针对每类编程加工中出现的过切或过切报警现象进行了分析。     

数铣刀具半径补偿过切现象分析与处理

分析了数控铣削刀具半径补偿的意义和过程;研究了几种常见的刀具半径补偿过切产生的原因,并采用一定的方法进行处理;最后提出了四种避免过切产生的方法。     

数控铣削加工中刀具半径补偿指令的应用

本文主要探讨的是在数控铣削加工中如何正确建立刀具半径补偿,避免建立刀具半径补偿时运动轨迹不合理引起的过切,并以西门子数控系统编程为例,说明刀具半径补偿建立的步骤。     

应用刀具半径补偿的过切现象分析

分析了圆弧与圆弧连接情况下刀具半径补偿值不同时刀心轨迹的变化,得出了刀具半径补偿值过大时可能产生的2种过切现象,提出了不发生过切的刀具半径补偿最大值的确定方法。     

由"刀具半径补偿"引起的过切现象

数控机床在使用刀具半径补偿时,如果使用不当,将会出现过切现象.文中针对过切现象进行了分析,提出了解决方案,并对建立和撤销刀具补偿轨迹提出了要求.     

浅析数控加工中的过切现象及应对策略

数控系统在使用刀具半径补偿功能时,由于数控编程或工艺处理不当等,易产生工件过切现象。针对以上过切现象,分析其原因并提出应对策略。     

刀具半径补偿功能及常见过切现象的规避

刀具半径补偿是数控加工中一个常用的指令，合理使用刀具补偿功能在数控加工中有着非常重要的作用，就刀具半径补偿功能及在数控加工中进行刀具半径补偿时常见的过切现象进行了讨论。     

刀具半径补偿中的过切现象及对策探讨

讨论在数控铣削加工中进行刀具半径补偿时常见的过切现象及其产生的原因,并提出相应的解决措施。     

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.