双工位连杆裂断机床控制系统研究

针对单工位连杆裂断机床,加工效率较低的问题,对连杆裂断机床结构、液压系统进行分析,提出了一种双工位连杆裂断机床。通过优化液压系统的控制策略,改进了连杆裂断的工艺流程,减少该机床连杆的加工时间。在三菱PLC为基础的控制系统上,增加了油箱液位检测、油箱液压油温度检测和液压压力检测,具有实时监控、自动运行、故障报警的功能。通过实验对比,改进后的机床不仅加工效率提高,而且连杆裂断的质量达到加工要求。     

连杆裂断与定扭矩装配螺栓一体机的研制

切槽、裂断和定扭矩装配螺栓是连杆裂断技术中的3道核心工序。国内外的连杆裂断与定扭矩装配螺栓设备,都是在两台机床上完成,设备成本高、加工效率低。能源消耗大,针对这些问题提出了连杆裂断与定扭矩装配螺栓一体机的构想。设计了一种可开合的空心顶销装置,具有顶紧连杆肩位和输送螺栓的双重作用,详细介绍了该一体机的总体设计方案,液、气压及控制系统,通过工艺试验,分析了裂断前与合装后连杆大头孔的直径变化,经验证完全满足工艺要求。     

连杆裂断机床的研制

连杆裂断技术是在连杆大头孔内表面预加工出两条应力槽,然后在孔内施加自内向外的裂断力将连杆剖分为杆体和杆盖两部分,通过自然形成的粗糙耦合面实现杆盖和杆体的精确啮合。裂断机床是发动机连杆裂断加工的核心设备,直接影响连杆的整体性能。介绍一种最新自行研制、结构简洁的连杆裂断设备,包括机床总体方案、结构特点、控制系统设计。经实验验证,机床完全达到设计要求。     

连杆裂断力参数的数值分析及其裂断质量研究

针对基于连杆裂断时所需裂断力的问题,利用断裂力学理论及有限元方法,采用KIC判据对与拉杆位移、裂断力及应力强度因子KI三者关系展开了研究。通过数值分析求解了应力强度因子达到断裂韧性KIC时拉杆所需的位移,以确定拉杆提供的裂断力。理论分析结果显示:裂纹槽宽为0.2 mm、槽深为0.4 mm的BYD473连杆,拉杆在位移27.25 mm处,连杆应力强度因KI达到断裂韧性KIC,此时连杆裂断所需的裂断力为32.75 kN,拉杆裂断力与应力强度因子KI呈线性关系。采用实验的方法分析了连杆裂断所需的裂断力及连杆的裂断质量。研究结果表明,连杆裂断时,所需的裂断力为32.75 kN,连杆裂断质量良好。数值分析与裂断实验数据对比结果显示,数值分析误差为11.4%,数值分析结果良好,可为液压系统参数的确定提供理论依据。     

基于PLC控制系统的电解加工机床改造

介绍了上海宝钢设备检修有限公司宝钢机械厂电解加工机床PLC自动控制系统。根据电解加工机床的要求,设计了控制系统的总体方案,阐述了该系统硬件设备配置及相应软件体系,机床主轴进给系统是由交流伺服电动机、光栅尺、滚珠丝杠等精密部件及PLC构成的全闭环控制系统。配备触摸屏作为人机接口,使系统控制界面友好,简单直观,便于操作。实际运行表明,该系统稳定可靠,满足生产工艺要求。     

煤矿综采工作面自动化技术研究与应用

在对当前机械与电气自动化技术研究的基础上,设计了一套基于MCU的井下综采工作面自动化系统,结合井下实际发展需求与分析,对硬件电路组成、软件系统功能进行了设计,实现了综采工作面自动化控制系统的稳定高效运行。     

基于PLC的台式钻床的自动化控制系统研究

为满足机床加工需求和提高加工效率,将传统台式钻床加工方式进行改造,设计了一种基于PLC自动化控制的钻床加工系统。以PLC作为控制器,换向电磁阀、伺服电机、液压缸为驱动设备的控制方法,重点讲解了液压回路、控制系统的硬件组成、电控原理以及PID参数对控制电机影响。最后,成功连接整个控制系统回路,并进行钻床调试和实验。实验数据表明:该钻床自动化加工控制系统设计合理,能够达到实际加工要求。     

新型连杆裂解机床电气控制系统设计

针对传统连杆裂解机床工序较多且裂解质量差,提出新型连杆裂解机床电气控制系统设计方案,新型连杆裂解机床主要由胀断部件和背压夹紧部件组成,采用FX2N-2DA模拟量输出模块对电液比例阀进行控制,采用PLC顺序控制程序进行控制,通过应用试验,设计的电气控制系统完全能够满足连杆裂解加工,极大地提高了生产率。     

液压缸综合试验台的控制系统设计

针对传统的液压缸试验台自动化程度低,系统精度不够,使用不方便等缺点,设计了一套适用于液压缸质量检测试验的综合试验台控制系统。该系统采用西门子PLC为控制核心,触摸屏为辅助设备;采用比例溢流阀及多传感器融合技术,运用压力闭环控制系统实现试验压力闭环控制保证了试验压力,应用比例调压系统实现自动、无级调压,无需人工调压。分析与设计了液压系统整体方案,分析了试验流程,对控制系统的PLC选型、I/O口分配、硬件接线、软件编程以及人机界面做了详细分析和设计。该系统检测精度高,自动化程度高,系统运行稳定,操作方便,满足生产要求。     

基于电液传动的多功能机床结构及控制系统设计研究

针对现有液压机床加工工序单一、自动化生产效率、以及加工精度不足等缺点,为实现机床高效率、多功能加工生产,设计了一种基于电液(液压和电机)传动的多功能机床及控制系统。首先,设计了多功能机床的基本结构、工作原理及工位分布;然后对机床控制系统进行了整体设计,包括主控器PLC选型、电液元器件型号选择、I/O分配以及PLC控制系统梯形图设计编程;最后,结合实际程序编程和安装完成的机床控制系统进行了现场实验数据采集测试,测试数据结果表明:设计的电液传动多功能机床及控制系统稳定效果好,能够快速实现多工序加工,提高了生产效率。     

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.