快走丝线切割机床断丝原因分析与对策

在快走丝线切割加工中经常会发生断丝现象,频繁穿丝降低了加工效率,重复切割导致加工精度下降.从断丝的根本原因入手,全面分析了加工中各种因素对断丝的影响,并提出有效减少断丝现象的解决对策和预防措施.     

快走丝线切割机床断丝原因分析与对策

在快走丝线切割加工中经常会发生断丝现象，频繁穿丝降低了加工效率，重复切割导致加工精度下降。从断丝的根本原因入手，全面分析了加工中各种因素对断丝的影响，并提出有效减少断丝现象的解决对策和预防措施。     

高速电火花线切割加工中断丝及对策

针对高速电火花线切割加工中经常会发生断丝现象,对原因进行了分析,提出了有效减少断丝现象的对策。     

电火花线切割加工断丝原因分析

高速电火花线切割加工中经常会发生断丝现象,断丝不仅会因为穿丝而降低加工效率,还会因为重复切割导致加工精度下降。文中从断丝的根本原因入手,全面分析了加工中各种因素对断丝的影响,指出影响断丝的主要因素是电极丝的直径、电极丝的磨损、电极丝的张紧力、工作液的介电性能和化学性能、机床的导丝结构以及加工参数。     

快走丝线切割断丝原因分析及对策

针对与快走丝线切割加工中经常会发生的断丝现象,从钼丝的选择、机床的机械部分、工作液、装夹工件、放电参数的选择等方面分析了断丝的原因,给出了减少断丝的措施,这些措施能切实有效地减少断丝现象发生.     

电火花线切割加工中的断丝现象与解决办法

数控高速走丝电火花线切割加工,首先必须保证在切割过程中不断丝。如果在切割工件过程中发生断丝,不仅会带来重新上丝的麻烦,造成一定的经济损失,而且会在工件上产生断丝痕迹,影响加工质量,严重时会造成工件报废。本文介绍了在线切割加工中的断丝问题,论述了产生断丝的原因,从线切割机床和工艺特点出发,对防止产生断丝的措施进行了探讨。     

线切割机防断丝装置

数控电火花线切割机床在加工过程中经常会出现断丝的现象,断丝情况一旦发生,操作人员就不得不进行拆丝、上丝等繁琐的操作,上丝过程不仅耗费大量工时,而且还会间接影响产品的加工精度和表面粗糙度。文中从线切割过程中导致断丝的根本原因切入,设计出一套线切割防断丝装置,以降低加工过程中断丝现象发生的几率,提高线切割机床的加工效率。     

高速走丝线切割断丝的原因分析及对策

高速走丝电火花线切割加工中的断丝问题一直是一个令人厌烦的问题。它使加工停顿并且不得不重新上丝，既浪费了大量材料和时间，破坏了加工表面的完整性，又增加了无人加工的困难。在正常情况下，断丝是由于电极丝的长期使用，电极丝变细、变脆而发生的。但是，断丝更多的是在非正常情况下发生的，因此总结、分析断丝的原因并制定相关对策就显得非常有意义。     

电火花线切割高速走丝机床的断丝研究及对策

详细分析了高速走丝电火花线切割加工中的各种断丝原因,并分别根据不同原因提出了解决对策,可切实有效地减少断丝现象的发生,对工业生产中的实际应用具有很好的参考价值。     

快走丝线切割机床高频电源故障及断丝原因探析

快走丝机床在线切割加工过程中经常会发生高频电源故障及断丝现象,此类故障的出现会影响加工精度、提高加工成本和劳动量及机器故障率、降低加工效率。文章对快走丝机床在线切割加工过程中常见的高频电源故障及断丝的原因进行分析研究。     

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。     

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.     

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....     

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.