基于双目视觉的轴类零件直径测量方法

通过双目视觉算法测量轴类零件的直径,搭建了双目视觉系统,对轴类零件实现了迅速精确的测量。首先利用张氏标定法对系统进行标定,然后通过图像处理得到结构光和轴类零件的交点坐标,再利用SURF+RANSAC算法对左、右相机采集图像立体匹配,最后计算出交点的三维坐标,解算出零件的尺寸大小。实验结果表明,测量误差均在0.1 mm之内。该方法精度高、运算速度快、稳定性好,适用于轴类零件直径测量。     

中心架支承块的改进

油缸缸体和轴杆类零件加工中,在机床上使用中心架是非。常普遍的现象(如车缸体长度、车油缸缸体内止口、轴类零件的车端面打中心孔等工序)。     

基于机器视觉的轴类零件识别

采用机器视觉手段进行轴类零件识别。通过采集待识别零件样本信息,利用MATLAB软件编程实现对样本的图像处理和轮廓提取,获得特征量信息。然后通过图像标定和亚像素最小二乘法进行直线拟合获得轴的边缘轨迹,完成轴的直径和同轴度识别。进行视觉识别结果和人工测量结果比较,结果表明,采用机器视觉进行轴类零件识别,相对误差为0.001,检测精度具有一定的可靠性,且检测速度快,便于实现批量化、在线实时检测,具有广阔的应用前景。     

快速检测小孔类零件的同轴度误差

因小孔类零件检测比较困难,使用快速检测装置有助于小孔类零件同轴度误差的检测速度和精度的提高。列举实例采用2种方法进行对比分析,解决了在批量生产条件下小型孔类零件的同轴度误差测量。     

通类管接头零件的UDF快速建模技术研究

通类管接头零件的类型和规格多种多样;若零件的类型或型号发生变化,设计者为了仿真分析、出图、工艺设计都需要重新设计模型,延长了产品的设计周期。为了提高设计效率,提出了用UDF快速建立通类管接头零件三维模型的方法。通过分析总结通类管接头零件典型通口结构的主要尺寸参数和参考约束,利用UG UDF命令定义通口UDF特征,形成UDF特征库;最后应用典型UDF特征对五通管接头零件进行综合实例建模,实现了通类管接头零件的快速设计。为通类管接头零件的快速设计提供了技术参考。     

一种大型套筒类零件加工的自定心专用夹具设计

套筒类零件形状精度和位置精度要求较高,孔壁较薄的套筒类零件在加工中容易变形。保证主要表面的位置精度和防止变形,是加工套筒类零件的关键。为加工大直径的套筒类零件设计制造了一种自定心专用夹具,解决了套筒类零件的装夹、定位问题,保证了零件的加工精度,提高了生产效率。     

基于光栅投影的三维测量技术

材质软和薄壁类零件,由于易变形,应用传统的接触式测量方法,满足不了要求。阐述了一种非接触式结构光光栅投影三维测量技术原理,给出了利用该原理测量零件的过程和测量结果。最后指出该方法在材质软和薄壁类零件测量方面有着广泛的应用情景。     

磨机筒体部同轴度的调整方法

<正>球磨机的回转体由进料端盖、筒体、出料端盖等3大基本零件,通过直径基本尺寸相等的各自圆柱形止口法兰盘相互对接,并由螺栓连接装配而成。球磨机同轴度指这3大基本零件装配后所形成的回转体部件的同轴度。如果1台球磨机的同轴度公差严重超差,会造成球磨机主轴瓦发热,甚至很快烧损主轴承巴氏合金瓦面,造成相连接的密封件密封不严,大小齿轮啮合不佳,齿轮传动噪声大、磨损快,并产生强烈振动,缩短使用寿命。本文将论述球磨机     

加工箱体、法兰盘和端盖类零件的通用钻模

在矿山机械制造或修配中应用图１和图２所示的加工箱　体、法兰和端盖等类零件的通用钻模,就能极大的提高产品质量、生产率或缩短新产品的试制周期。１箱体零件加工通用钻模１．１结构和工作原理如图１所示,１为钻模定位底板,钻孔时,把它的定位止口装在已加工好的箱体孔径中。定位止口按几个不同的标准尺寸做成阶梯形,可以装置在箱体不同的孔径上。心轴２紧定在钻模定位底板１上。可调活动钻模板３和４以铰链与心轴２相配合。精密螺杆９和螺母８是用来调节两个可调活动钻模板２和４距离位置的,从而达到所要求两孔之间的角度或弦长。在…     

关节臂在矿用减速器测量中的应用

介绍了关节臂式坐标测量机的结构原理,比较了三坐标测量与常规测量的区别,应用关节臂式坐标测量机测量了矿用减速器浮动密封配合面的尺寸偏差、止口同轴度,分析了减速器漏油原因,并采取了处理措施,解决了减速器漏油问题。     

Hydrocyclones in dewatering circuits

When hydrocyclones are used in dewatering circuits it is important to know the potential impact of trying to balance the flow of liquid to the overflow and underflow streams and the size distribution of the solids in these respective streams. The diameters of the vortex finder and spigot play important roles in this balance but neglecting the effect of the feed size distribution could also severely impact the final outcome. This is particularly the case where the transport of coarse particles through the spigot becomes a significant factor.This paper presents a model which accounts for these effects and examines its capability with a data set of over 40 experimental trials with a 225 mm cyclone with a broad range of operating conditions (solids concentration, vortex finder and spigot diameters and flow rates). The model’s capability was then subsequently subjected to a further examination by altering the feed size distribution so that it contained a significantly greater amount of material in the size range near the separation size (0.090–0.200 mm). Good results were obtained in both cases.     

Fundamentals on the spigot capacity of dense medium cyclones

The capacity of dense medium cyclones is often restricted by the solids-carrying capacity of the underflow, referred to as spigot capacity. Cyclone manufacturers normally recommend the spigot capacity for a cyclone of a particular size; however, it is not clear how these capacities are determined and whether they can be increased. In the literature, spigot capacity has previously been associated with roping flow at the underflow, although this notion has neither been clearly proven nor disproved. Furthermore, the effect of overloading the spigot on the operation of a dense medium cyclone has not been adequately studied.In this study, test-work on a 165 mm diameter dense medium cyclone was performed to investigate its spigot overloading behaviour. This work established clearly that spigot capacity was reached at the onset of roping flow, and that there was a critical underflow ore concentration at which roping/spigot overloading occurred. This ore concentration was shown to be a useful tool in anticipating and avoiding spigot overloading. Spigot capacities obtained in this study were higher than those specified in the DSM handbook, indicating that dense medium cyclone could possibly be operated at higher spigot capacities. However, separation efficiencies were not monitored during this investigation.     

CFD modeling and analysis of the multiphase flow and performance of dense medium cyclones

A computational fluid dynamics (CFD) model is proposed to describe the multiphase flow in a dense-medium cyclone (DMC). In this model, the volume of fluid (VOF) multiphase model is first used to determine the initial shape and position of the air core, and then the so called mixture model is employed to describe the flows of the medium, coal particles and air, where the turbulence is described by the Reynolds stress model. The validity of the proposed approach is verified by the reasonably good agreement between the measured and calculated results in terms of separation efficiency. On this base, this model is used to quantify the effects of the ratios of spigot to vortex finder diameters (U:O) and medium to coal (M:C) on performance. The results are shown to be generally comparable to those reported in the literature. It reveals that when vortex finder or spigot diameter is varied at the same U:O ratio, the offset and medium split nearly remain the same, however, the coal feed rate and E_p are different under the conditions considered. It is also shown that the fish-hook phenomenon is observed when spigot diameter is equal to or slightly larger than vortex finder diameter, and a normal operation becomes less stable with decreasing U:O ratio. The key phenomena predicted are explained by the calculated inner flows.     

量测技术在北京鹰山特大断面隧道中的应用

针对鹰山隧道断面大、跨度大、埋深浅、覆跨比小等特点，设置了５个量测断面，对洞壁水平位移、顶拱垂直位移、地表下沉量等进行了量测，量测结果显示，位移值远小于规定的允许值，为快速、优质、安全施工创造了先决条件。     

多路温度测量光纤变送器

阐述了多路温度测量光纤变送器的原理及结构,对其中的一些主要部件作了详细介绍,给出了部件参数,并着重讲解了其中的数据采集系统。实际使用证明,该测温系统具有可靠性高、测温精度高等特点。     

CFD validation for flyash particle classification in hydrocyclones

The investigation pertains to establishing a simulation methodology for understanding the flyash classification characteristics of a 76 and 50 mm diameter hydrocyclone where the work was carried out using commercially available CFD software. Comparative results on the simulated and experimental water throughput, split values are presented. Results indicted that there is a good match in water split between the experimental and simulated values with error values below 10% at different hydrocyclone designs. Further a discussion is made on the flow features at comparable ratio of cyclone diameter to spigot opening in the 76 and 50 mm designs. The vertical core region around the cyclone axis having static pressure equal to or below the atmospheric pressure is examined to be increasing in diameter from bottom of the spigot opening till the interface where vortex finder joins the main cylindrical cyclone body and remains more or less similar at the vortex finder outlet. The diameter of this zone at the spigot outlet is 0.6 and 5.4 mm at 3.2 and 9.4 mm spigot openings in case of 50 mm diameter hydrocyclone. The diameter of the core at spigot outlet is found to be around 9.2 and 11 mm at 15 and 20 mm for spigot openings in case of 76 mm diameter hydrocyclone.Classification of flyash particulates is simulated through discrete phase modeling using particles injection technique and the simulated results are further validated with suitably performed experiments. With 50 mm diameter hydrocyclone, reasonable predictions are observed at 9.4 mm spigot opening. Considerable deviation in particle distribution points with this hydrocyclone is observed at narrowest spigot diameter of 3.2 mm. The simulated values of d₅₀ in case of 50 mm diameter hydrocyclone are 8 and 10 μm at 9.4 and 3.2 mm diameter spigot openings. Better predictions are obtained with 76 mm diameter hydrocyclone at both 10 and 15 mm diameter spigot openings. Similarly, the simulated d₅₀ values are 14 and 20 μm at 15 and 10 mm diameter hydrocyclones. Possible reasons for deviations in the results relating the spigot opening, solids concentration at the underflow and in turn role of slurry viscosity on the air core diameter are proposed.     

Computational study of the multiphase flow and performance of dense medium cyclones: Effect of body dimensions

This paper presents a numerical study of the gas-liquid-solid flow in 1000 mm dense medium cyclones (DMCs) with different body dimensions, which includes the spigot diameter, cylinder length, cone length and inlet size by means of a computer model which we recently proposed. In this model, mixture multiphase model is used to describe the flow of the dense medium (comprising finely ground magnetite contaminated with non-magnetic material in water) and the air core, where the turbulence is described by the well-established Reynolds Stress Model. The stochastic Lagrangian Particle Tracking method is used to simulate the flow of coal particles. It is found that the spigot size is very sensitive to the performance. The operational head and medium split reporting to overflow, decrease dramatically as the spigot diameter increases. The density differential decreases rapidly, and then passes through a minimum and increases slowly. The long body including cylinder and cone is helpful to particle separation, particularly for fine and heavy particles. The inlet size plays a remarkable role on the performance on DMCs. The operational head, the density differential and the medium split increase dramatically as the inlet size decreases. Both the upward flow and the downward flow become very strong in the DMC with a small inlet when medium feed rate is constant, which results in a very low Ep.     

智能气动测量系统的研究

阐述了实现高精度、宽测量范围的智能化气动测量系统的工作原理和主要设计方法 ,介绍了用于提高测量精度、扩展测量范围和实现智能测量的建立在软硬件基础上的自校准三次测量法、增益可编程控制测量放大器和非线性修正技术的工作原理 ,给出了部分软件的流程图 ,并对误差修正前后的测量系统的精度进行分析。     

烧结混合料在线测水方法研究

本文主要论述了三种在线式水分测量方法的测量原理和烧结混合料水分在线测量的难点,对几种测量方法应用到烧结混合料实时水分测量的特点进行了分析。分析结果表明,微波法对于烧结混合料水分的在线测量具有良好的适用性和广阔的应用前景。     

水力旋流器沉砂口直管段对性能的影响

沉砂口直管段是水力旋流器的一个重要构件。通过它可以改变旋流器内空气柱的大小及特征，从而显著提高旋流器的沉缩性能，并可改善分级性能。它的改变对分流比有一定的影响，而对处理能力几乎没有影响。所得研究结果对如何选择旋流器沉砂口直管段的长度和内径具有重要的指导意义。