数控回转工作台设计

通过使用双导程蜗杆蜗轮消隙结构,大大提高了数控回转工作台的回转定位精度,床身使用整体四导轨结构,滑座的直线运动和工作台的回转运动均使用静压导轨结构,满足了数控回转工作台最大承重160 t的实际需要。     

立式车床工作台导轨润滑系统改进

C52系列双柱立式车床工作台平面导轨原采用动压导轨副结构,为适应对机床承载能力、回转速度、动态精度提高的要求,并适应数控化升级改进需求,将工作台导轨副改为静压导轨副。介绍了动压与静压两种导轨副的润滑系统。     

TK68125A六轴五联动数控镗铣床主轴低头问题的解决

根据“十五”国家科技攻关计划《大型镗铣数控机床及关键技术开发》课题中的专题项目《TK68125A落地式数控镗铣床》，开发设计了一台落地式六轴五联动数控镗铣床。立柱横向移动为X轴，拖板带动滑枕在立柱上上下移动为Y轴，滑枕作前后进给为Z轴，固定工作台旁边附加的数控转台为B轴，A轴、C轴固定在滑枕头部作回转运动。     

齐重25米数控重型立式铣车床通过验收

<正>2017年11月25-26日,齐重数控装备股份有限公司牵头承担的04专项"数控立柱移动立式铣车床"课题,在用户现场通过了验收。该课题由齐重数控装备有限公司承担,参加单位有清华大学和哈尔滨工业大学。课题开展了具有独立高精度分度功能的超重超大型工作台C轴结构、工作台静压导轨技     

大型滚齿机回转工作台设计

以SKG13050型数控滚齿机回转工作台为例,介绍了滚齿机回转工作台的静压导轨、回转定心轴承、蜗轮蜗杆副侧隙调节等结构和主要零件的设计,回转工作台零部件经过采购、制造、安装,与床身、立柱、滚刀架部件和电气系统、液压系统、控制系统等装配调试,通过齿轮试切和机床投产滚切实践,回转工作台设计满足滚齿机性能要求。     

TK68125A主轴低头问题的解决

TK68125A是根据“十五”国家科技攻关计划《大型镗铣数控机床及关键技术开发》课题中的专题项目《TK68125A落地式数控镗铣床》开发设计的一台落地式六轴五联动数控镗铣床。立柱横向移动为X轴,滑板带动滑枕在立柱上上下移动为Y轴，滑枕作前后进给为Z轴，固定工作台旁边附加的数控转台为B轴，A轴、C轴固定在滑枕头部作回转运动，其中X、Y、Z、A、C五轴联动。     

一种闭式静压回转工作台新型结构设计

针对原有的滚动导轨、动压导轨、开式静压导轨等结构不能满足工作台高回转精度的要求,设计了闭式静压导轨高精度回转工作台,它是当今机床工作台领域的一种新技术。     

TK68125A型数控落地铣镗床

江苏多棱数控机床股份有限公司开发的该机床是一台大型多功能数控铣镗床。机床具有6个数控坐标轴,5轴联动。机床结构采用全动柱落地式固定工作台(1.6m×4m,旁边附加B轴数控转台),立柱横向移动,Y轴(滑枕拖板)在立柱上上下移动,Z轴(滑枕)作前后进给,A轴、C轴固定在滑枕头部作回转,6轴5联动(X,Y,Z,A,C轴联动)运动。机床X轴采用滚柱滚动导轨,双齿轮齿条消隙机构进给。Y轴采用滚柱滚动导轨,滚珠丝杆进给;Z轴为滑枕,截面尺寸650m m×450m m(高×宽),上下各二根滚珠滚动导轨,滚珠丝杆进给。A,C轴均采用双齿轮消隙机构驱动,交叉滚柱轴承支承。…     

滚动与滑动复合导轨重型数控回转工作台及其驱动机构的应用

滚动与滑动复合导轨重型数控回转工作台可承载重大型工件,回转定位精度较高,接触刚性好,减小摩擦力.     

卸荷开式静压导轨在数控立式钻床上的应用

介绍了液体卸荷开式静压导轨应用于数控立式钻床上的优点,根据数控立式钻床的整体结构方案及其工作台导轨的工况,确定了卸荷开式静压导轨的结构方案,提高了工作台导轨接触刚度,解决了低速下工作台不爬行问题。     

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.