特细金属丝整经筒子架及单丝张力控制研究

整经是重要的织前工艺,单丝张力是否均匀是整经质量最重要的衡量指标之一。筒子架作为整经机主要组成部分,是整经中单丝张力控制的关键。文中介绍了一种特细金属丝整经机筒子架,主要应用在高精细金属丝网织造中。首先分析了特细金属丝整经的特点与难点,然后通过对比矩形筒子架和V形筒子架各自优缺点,设计了V形对称错位结构的筒子架。通过单丝张力控制方式进行了对比试验,发现重锤摩擦盘式控制方式较无单丝张力控制方式、重锤张力杆式控制方式在输出响应的快速性、稳定性及准确性方面更佳,且能将单丝张力误差控制在±0.03 N。     

双伺服整经机的恒张力控制

系统中采用了双伺服电机对整经轴、牵引轴的转速进行调节,使系统能够更快更好的达到预定要求,形成恒定的整经张力,而且系统中同时应用了电子齿轮功能,通过闭环控制系统有效的保证了整经工艺中的恒张力.     

MZD型整经机液压系统介绍

本文介绍了西德Schlafhorst 公司生产的MZD 型整经机液压系统。该机采用了机、电、液一体化的结构,满足了目前整经向高速、宽幅、大卷装发展的要求,对国内新型整经机的研究具有一定的参考价值。     

自动PET薄膜收卷机机械系统设计

通过分析PET薄膜特性和自动PET薄膜收卷机的工作原理,对PET薄膜收卷机的功能提出了要求,并设计出自动PET薄膜收卷机的机械结构。通过采用张力控制系统和纠偏系统,保证薄膜在生产中所受张力恒定,能够不被划伤,运行过程中不跑偏,并确保收卷时料卷的端部整齐。在此基础上,研制了自动PET薄膜收卷机的样机,并分别对不同厚度的PET薄膜进行了连续实验,实验结果表明：设备运行良好、收卷整齐、自动化程度高,各项性能指标都达到了设计要求。     

高速走丝线切割机张力控制器

<正> 我国制造的高速走丝数控线切割机床具有造价低、使用方便,生产率高等优点,目前全国拥有量已超过万台,是模具加工的主要设备。然而,高速走丝线切割机在加工精度方面尚不如国外低速走丝线切割机,其主要原因是走丝系统稳定性不够,为此我们设计了一种张力控制器,其功用、结构原理如下:一、功用1.减少以至消除电极断丝,提高劳动生产率。2.通过粗、精张力调整、稳定电极丝的张力,从而提高加工精度和降低表面粗糙度。3.及时消除因电极丝伸长而引起的张力不稳现象、减少电极丝的抖动。二、结构原理1.结构原理见图1卷丝筒左边部分是张力控制器的紧丝装置,这部分是通过SD 电     

PLC和触摸屏在塑料片材收卷机中的应用

塑料片材收卷机位于塑料生产线的终端,将定幅的产品完成自动收卷,为满足生产线自动化及收卷质量的要求,采用双工位变频收卷,电气控制系统使用工业级PLC和触摸屏相结合。在介绍双工位收卷工作流程的基础上,分析了恒张力控制原理,并详细论述控制系统的工作原理、硬件设计及触摸屏界面设计。     

新型多股簧钢丝动态张力控制系统研究

根据多股簧加工原理,为提高加工精度和质量,必须对每股钢丝进行张力控制,多股簧加工机床中钢丝张力控制系统又须在作旋转运动的线盒架上实现,通过与张力控制中最常用的磁粉控制方法相比较,针对多股簧动态系统要求,采用摩擦轮的方法,设计了一种新型的张力执行机构和气压控制系统,系统简单可靠,解决了运动机构上大张力控制系统中体积、质量等限制等问题。从比例阀张力控制系统结构及气体动态特性方程出发,建立质量流模型和传递函数模型,推导出系统结构方框图,满足了实际控制需求。     

数控包带头结构设计与张力控制

阐述了数控包带机包带头包扎绝缘带的工作原理,提出了基于PLC控制和变频电动机驱动的横张力控制系统策略.针对数控包带机包扎绝缘带到线圈上的包扎角度的要求,文中对转角系统中几个关键零件进行了机械结构设计.数控包带头设计中针对包带机工作时需要频繁换装包带卷的要求,增加了对于包带盘简易装卡的设计.该数控包带头的主要特点是能够自动控制张力和包扎角度,包带效率高,能够为进一步研究开发实用型数控包带头提供基础.     

新型宽幅动力锂电池挤压式涂布机的研制

为了减少涂布工艺中涂层干厚度误差,提高动力锂电池极片生产质量,提升生产效率,研制出一种新型宽幅动力锂电池挤压式涂布机。挤压式涂布机结构主要有大理石平台和漂流烘干箱构成,这种设计有效提高设备耐用性和物理精度,并消除了生产过程中的物料损伤。控制系统采用三菱张力控制器LE-40MTB-E和张力传感器LX-015TD构成闭环控制系统,进行恒张力控制;采用卷径计算单元LE-40MD和变频器构成料带恒速控制,以应对在生产过程中的卷径不断变化。经过严格测试证明,系统运行稳定可靠,各种技术参数符合性能指标,其中单面涂布干厚度误差比传统设备降低了30%左右,有效解决了传统涂布工艺中涂层精度不高问题。     

薄膜张力控制系统的建模与设计

鉴于薄膜收换卷时的张力大小及平稳性对收卷质量具有决定性的影响,针对流涎机收卷系统的动态过程,分析了张力与收卷线速度、卷径及转速之间的动力学关系,提出了张力控制原理,并分析了薄膜在收换卷时收卷电机转速的变化补偿规律。在此基础上,设计了薄膜在收换卷时的张力控制系统,通过控制速度差对张力进行间接控制,同时采用BP神经网络PID控制器调节收卷转速对张力进行直接补偿。仿真对比结果表明,该控制器动态响应好,抗干扰能力强。实际应用实例也证明该控制方法张力控制精度高,控制高效可靠, 对改善系统的动态特性和提高薄膜的收卷质量有着重要意义。     

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.