PLC及伺服技术在齿轮专用铣床改造中的应用

介绍一种普通铣床改造成齿轮加工专用铣床的方法,其控制系统主要包括小型可编程逻辑控制器和伺服驱动器.改造后的铣床不仅加工精度有了保证,而且大大降低了操作工的劳动强度,提高了生产效率.     

大模数齿轮数控铣削加工的应用研究

对普通铣床进行数控改造,使用圆柱铣刀按照渐开线的发生原理.采用展成法的方式直接加工齿轮模数为16～40mm的渐开线齿形,由于在数控加工中使用渐开线的基圆来进行程序参数的转换计算,所以齿轮的加工精度能够得到有效地保证.本文通过实例加工阐述数控改造的原理、铣床结构的改造以及编程参数的转换计算,并对齿轮加工精度提高的成因和效果进行了分析.     

大模数齿轮数控铣削加工的应用研究

对普通铣床进行数控改造,使用圆柱铣刀按照渐开线的发生原理,采用展成法的方式直接加工齿轮模数为(16～40)mm的渐开线齿形,由于在数控加工中使用渐开线的基圆来进行程序参数的转换计算,所以齿轮的加工精度能够得到有效地保证.本文通过实例加工阐述数控改造的原理、铣床结构的改造以及编程参数的转换计算,并对齿轮加工精度提高的成因和效果进行了分析.     

用经济型数控铣床加工蜗杆的研究与实践

分析了蜗杆加工的特点,针对存在的问题,应用数控技术对普通分度头进行改造.通过实践总结分度头误差产生的原因,找到解决的措施,为蜗杆加工和经济型数控铣床配套改造数控分度头,开辟了经济可行的新途径.     

基于普通铣床的数控化改造

世界先进制造技术兴起和不断成熟,数控加工技术提出了更高的要求.数控机床已成为衡量一个国家机械制造水平的重要标志.数控铣床是一种加工功能很强的数控机床.分析了普通铣床数控化改造的必要性,数控化改造的特点,数控化改造的条件,提出了数控化改造的内容,数控系统的选择,数控改造中主要机械部件改装探讨,数控化改造的一般步骤.     

普通铣床的数控改造

利用微机改造普通机床，是目前设备改连急需解决的问题。文中介绍了采用JWK-15T型单片机系统改造普通铣床，改造后的普通铣床能保证加工零件的质量精度要求，特别是对复杂零件的加工，效果更为显著。     

X52K铣床数控化改造

凸轮是农用三轮车上的常见零件,在普通铣床上进行加工时,其生产效率低,加工精度不高。我们采用经济型数控改造技术对某机械厂的一台X52K型立式铣床进行了数控改造,用于凸轮的加工,改造后其加工精度高,能保证产品的质量,而且由于生产效率的提高,生产成本也显著下降。     

蜗轮范成法加工的数控改造及应用

数控技术优势的显著特征之一就是在实际应用中,可根据被加工零件所需的运动要求,应用范成法的加工方式对机床进行数控改造,可以收到理想的效果.论文论述在缺少专用设备的前提下,数控改造普通卧式铣床加工蜗轮.此数控改造方式的长处在于:利用数控系统螺纹指令和锥螺纹指令的加工功能,巧妙地转化为控制进行蜗轮的数控加工,拓宽了数控系统的加工功能和实际应用的范围.并应用数控技术的优势,减小或消除累积蜗轮在加工的齿距误差,因此使得蜗轮的加工精度和蜗轮传动的平稳性大为提高.通过改造实例阐述数控改造的原理、铣床结构的改造以及程序编制中参数的转换计算,并对蜗轮加工误差控制和精度提高的成因及加工效果进行分析.     

渐开线型零件切削加工运动设计

从涡旋压缩机转子和定子粗加工比较困难的实际出发,对渐开线形成的惯用方法进行了改造并应用于铣床,从而得出几种利用普通铣床加工渐开线型零件的方法,进而对该加工方法中的辅助运行进行了分析。     

分度类零件专用机床设计

针对分度类零件的加工特点,将普通立式铣床改造为分度类零件加工专用机床,把铣床原丝杠螺母进给传动装置改造成液压传动方式。其分度装置利用步进电机驱动,对F125普通万能分度头进行数控化改造;控制装置采用PLC取代原有的继电器控制。改造后的专用机床对分度类零件可以实现快进-减速快进-工进-快退-减速快退-分度-快进的自动循环加工。通过对矩形齿快慢速转换离合器零件的加工实验证明,该机床加工分度类零件可以提高生产效率、减少操作失误及提高加工精度。     

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.     

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....     

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.     

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.