Y9420 Gear Chamfering Machine

Y9420 Gear Chamfering Machine is ahigh efficiency machine tool designedby the Chongqing Machine ToolsWorks to meet market demand. The machineemploys the principle of cool extrusion anduses a special chamfering tool which drivesthe work piece to rotate and achievechamfering. It features no tool tracks and noburr on the ends. Multiple cutters can beused to process cluster gears, and thechamfering can be realized on either oneside of the tooth or on both. It is an idealpiece of equipment for automobiles, machinetools and gears manufacture to chamfer anddeburr disk type gears, spur and helical shaftgears and cluster gears.

Chamfer Matching在CT和MRI图像匹配融合中的应用

医学影像中的CT和MRI图像的精确匹配融合能为临床提供全面、丰富的诊断信息。文中首先对CT图像正常脑组织边缘做距离变换 ,形成距离图像 ,然后利用MRI图像正常脑组织边缘作为模板 ,实现了CT和MRI图像的精确匹配。在此基础上完成了CT和MRI的信息融合。文中算法适用于CT和MRI的匹配 ,并对SPECT ,PET 。

黏胶纤维筒子纱活性染料染色内外层色差控制

调整设备、工艺等,改善及控制黏胶纱线染色前松筒的工艺参数,结合在染色过程中控制染料的上染速率,实现纱线均匀上染的目的,保障筒子染色后内外颜色的均匀性。分析了设备参数、筒子密度、染色工艺对匀染性的影响,棉型黏胶纱染色松筒密度0.2~0.3 g/cm^(3)(卷硬度30~20),线速800 r/min,调节筒子横动致最大范围,下机质量800 g/筒;对络好的半成品筒进行倒角,角度为80°圆弧状。根据纱线特点,设计正反向循环,正向4 min、反向6 min,以保证染液与纱线均匀接触;选择上染速率一致或接近的三原色,采用一浴二步法染色,在染色过程中调节助剂加入频次,元明粉及碱粉各分2次加入,染色过程中以2℃/min升温至60℃保温,在染料吸附及固着阶段做到缓、慢、匀、透,从而达到染料均匀上染的效果。

基于改进Chamfer匹配的台标识别

已有电视台台标的识别技术多基于视频流处理,实时性较差,且对半透明台标识别效果不佳。为此,提出一种基于改进Chamfer匹配的台标识别方法。利用Canny算子提取台标边缘颜色及梯度方向,采用RANSAC算法对台标边缘进行优化,通过距离变换计算边缘梯度方向的距离图,并基于距离最短准则对其识别。实验结果表明,该方法能实现台标的单帧识别,克服半透明台标的识别难题,平均识别率达97.7%,平均识别时间为801 ms。

阀控式铅酸电池结构与包装精益设计

为了优化新能源动力阀控式铅酸蓄电池包装工艺,采用优化电池结构设计的方案,设计出嵌槽倒角式电池盖。将配套的提手绳由嵌槽嵌入圆孔,提高了安装速度。电池装箱后,将配套的提手管置于电池盖的顶面与正面倒角A处,将配套的螺栓置于电池盖的侧面与正面倒角B处,省去泡沫垫板。纸箱封合后外观平整。用嵌槽倒角式电池盖组装的阀控式铅酸蓄电池与传统的阀控式铅酸蓄电池相比,不仅提高提手绳安装速度约1倍,又将提手绳、泡沫垫板和纸箱三者的成本节约367.65~424.05万元/a。

Experimental Study on Wear Characteristics of PCBN Tool with Variable Chamfered Edge

Owing to heavy dynamic and thermal loads, PCBN tools are seriously worn during hard cutting, which largely constrains the improvement of their machining performance. Therein, the chamfered structure of a cutting edge has a notable influence on the tool wear. Thus, a comparative study was carried out on the wear morphology and wear mechanism of PCBN tools with either a variable chamfered edge or an invariable chamfered edge. The results indicate that, for a PCBN tool with a variable chamfered edge, the rake wear area is far from the cutting edge and slowly extends toward it. A shallow large-area crater wear occurs on the rake face, and the flank wear area has a long triangular shape with a smaller wear area and width, and the cutting edge remains in a good state during the cutting process. In contrast, for a PCBN tool with an invariable chamfered edge, a deep small-area crater appears on the rake face, and the wear area is close to the cutting edge and quickly extends toward it. Thus, it is easy for chips to accumulate in the crater, resulting in large-area and high-speed wear on the flank face. In addition, the tool shows a weak wear resistance. In the initial wear stage, the rake wear mechanism of the two cutting tools is a mixture of abrasive, oxidation, and other types of wear, whereas their flank wear mechanism is dominated by abrasive wear. With an aggravation of the tool wear, the oxidation and diffusion wear mechanism are both increasingly strengthened. The rake wear of the cutter with a variable chamfered edge showed an obvious increase in the oxidation and diffusion wear, as did the flank wear of the cutter with an invariable chamfered edge. This study revealed the wear mechanism of the PCBN tool with a variable chamfered edge and provided theoretical and technological support for its popularization and application in the machining of high-hardness materials.

Influence of the Hole Chamfer on the Characteristics of a Multi-hole Orifice Flowmeter

In order to analyze the influence of the hole chamfer on the metering performances of a Multi-hole Orifice Flowmeter and optimize the related orifice structure,a multi-hole orifice flowmeter with DN80 and throttle ratio of 0.45 was considered in the present study.The flow field characteristics were determined in the framework of a CFD technique.The results show that the multi-hole orifice flowmeter with filleting transition around the throttle orifice has higher accuracy in a wide range of the space of parameters,and is more suitable for accurate measurement of fluid in process control.

Experimental and numerical investigation of a Hall thruster with a chamfered channel wall

A discharge channel with a chamfered wall not only has application in the design of modern Hall thrusters, but also exists where the channel wall is eroded, and so is a common status for these units. In this paper, the laws and mechanisms that govern the effect of the chamfered wall on the performance of a Hall thruster are investigated. By applying both experimental measurement and particle-in-cell simulation, it is determined that there is a moderate chamfer angle that can further improve the optimal performance obtained with a straight channel. This is because the chamfering of the wall near the channel exit can enhance ion acceleration and effectively reduce ion recombination on the wall, which is favorable to the promotion of the thrust and efficiency. However, the chamfer angle should not be too large; otherwise, both the density of the propellant gas and the distribution of the plasma potential in the channel are influenced, which is undesirable for efficient propellant utilization and beam concentration. Therefore, it is suggested that the chamfer shape of the channel wall is an important factor that must be carefully considered in the design of Hall thrusters.

Slenderness Ratio Effect on the Eccentric Compression Performance of Chamfered Laminated Bamboo Lumber Columns

Eccentric compression tests on 15 chamfered laminated bamboo lumber(LBL)columns with a height ranging from 600 to 3000 mm were conducted in order to study the eccentric mechanical performance.The failure of all specimens was caused by the crack of bamboo fiber in the tensile region.When the ultimate strength was reached,except specimens with a height of 600 mm,all other specimens could bear large deformation,showing good ductility.The lateral displacements of the specimens under eccentric compression were approximately para-bolic in the direction of column height.The ultimate bending moment of LBL columns with different slenderness ratios under compression with the same initial eccentricity was a fixed value.The relationship between ultimate capacity,axial displacement,lateral displacement,and slenderness ratio was analyzed based on test results.It was found that the plane section assumption could be used to express the stress and strain distribution of chamfered LBL columns under eccentric compression.A method for calculating the ultimate bearing capacity was proposed using a constitutive model based on the Ramberg-Osgood relation and the empirical formula for calculating the ultimate capacity was given on the basis of the former research as well as the test results in this paper.

Matching characteristics of magnetic field configuration and chamfered channel wall in a magnetically shielded Hall thruster

To date, the selection of the magnetic field line used to match the chamfered inner and outer channel walls in a magnetically shielded Hall thruster has not been quantitatively studied. Hence, an experimental study was conducted on a 1.35 k W magnetically shielded Hall thruster with a xenon propellant. Different magnetic field lines were chosen, and corresponding tangentially matched channel walls were manufactured and utilized. The results demonstrate that high performance and a qualified anti-sputtering effect cannot be achieved simultaneously. When the magnetic field lines that match the chamfered wall have a strength at the channel centerline of less than 12% of the maximum field strength, the channel wall can be adequately protected from ion sputtering. When the magnetic field lines have a strength ratio of 12%–20%, the thruster performance is high. These findings provide the first significant quantitative design reference for the match between the magnetic field line and chamfered channel wall in magnetically shielded Hall thrusters.

Experimental Evaluation on Grinding Texture on Flank Face in Chamfer Milling of Stainless Steel

The surface quality of chamfer milling of stainless steel is closed related to the products of 3 C(Computer, Communication and Consumer electronics), where a cutter is a major part to achieve that. Targeting a high-quality cutter,an experimental evaluation is carried out on the influence of grinding texture of cutter flank face on surface quality.The mathematic models of chamfer cutter are established, and they are validated by a numerical simulation. Also the grinding data are generated by the models and tested by a grinding simulation for safety reasons. Then, a set of chamfer cutting tools are machined in a five-axis CNC grinding machine, and consist of five angles between the cutting edge and the grinding texture on the 1 st flank faces, i.e., 0°, 15°, 30°, 45° and 60°. Furthermore, the machined cutting tools are tested in a series of milling experiments of chamfer hole of stainless steel, where cutting forces and surface morphologies are measured and observed. The results show that the best state of both surface quality and cutting force is archived by the tool with 45° grinding texture, which can provide a support for manufacturing of cutting tool used in chamfer milling.

Visual detection method of chamfer Ron the root bottom of textile workpiece roller

Roller is an important workpiece of automatic spinning machine. Only if the chamferR on the root bottom of roller＇s guide pillar meets processing accuracy requirement can the end face of one roller＇s guide pillar match the correct position of another roller＇s end face on the guide hole. Therefore, the size of chamfer R on the root bottomof the roller＇s guide pillar has an important influence on the operating state of automatic spinning machine. In order to achieve the rapid, automatic and precise measurement of chamfer R on the root bottom of roller, an auto detection system }＇or roller~ s chamfer based on computer vision technology is proposed. Firstly, the principle of measurement based on computer vision technology is introduced. And then the extraction method of charnfer^s characteristic parameters is presented, which uses image processing technique to obtain these characteristic parameters by means of collected images of roller contour, including extraction of region of interest, extraction of subpixel precise edge, segmentation of arc and line, fittingof geometric primitives, etc. Finally, after experimental verification, the measurement error is within ＋ 5 μm and repeated accuracy is 0.1 pm. The results show that this measurement method is applicable to not only the chamfer on the textile workpiece, but also the workpieces of shaft type with various of sizes.

C-LOG： A Chamfer distance based algorithm for localisation in occupancy grid-maps

A novel algorithm for localising a robot in a known two-dimensional environment is presented in this paper. An occupancy grid representing the environment is first converted to a distance function that encodes the distance to the nearest obstacle from any given location. A Chamfer distance based sensor model to associate observations from a laser ranger finder to the map of the environment without the need for ray tracing, data association, or feature extraction is presented. It is shown that the robot can be localised by solving a non-linear optimisation problem formulated to minimise the Chamfer distance with respect to the robot location. The proposed algorithm is able to perform well even when robot odometry is unavailable and requires only a single tuning parameter to operate even in highly dynamic environments. As such, it is superior than the state-of-the-art particle filter based solutions for robot localisation in occupancy grids, provided that an approximate initial location of the robot is available. Experimental results based on simulated and public domain datasets as well as data collected by the authors are used to demonstrate the effectiveness of the proposed algorithm.

并列切角方柱风致干扰效应的大涡模拟研究

针对并列切角高层建筑间的干扰影响问题,本文采用大涡模拟方法研究雷诺数22 000的均匀流场下并列切角(切角率10%)方柱的干扰效应。基于模型的网格收敛性分析及模型准确性验证,对比分析不同间距比下并列切角方柱的气动干扰效应和流场分布,并探寻风压干扰效应的影响规律和形成机理。结果表明:对于并列切角方柱,平均阻力系数主要呈放大效应,脉动升力系数主要呈减小效应。在并列切角方柱处于小间距(B/L=1.2)时,由于风与壁面的相互作用,产生风压力,风压力与方柱表面力叠加,对正压区域产生加强效果,表现为放大效应,对负压区域进行削弱,出现减小效应;当B/L=1.5时,结构干扰最剧烈,其中相邻立面后流场的切角处放大效明显,干扰因子最大值为2.58;当B/L≥4.0时,除相邻立面外的其他立面与切角干扰效应趋于消失;当B/L=8.0时,相邻立面仍然存在28%的放大效应。

小倒角结晶器窄面铜板角部冷却结构优化

为解决某钢厂板坯小倒角结晶器高拉速生产时铸坯角部纵裂纹比例增大问题,在原型倒角分叉槽冷却结构基础上,提出不同圆孔直径和圆孔位置的1孔1槽方案。建立窄面铜板和冷却水三维传热耦合模型,并通过工业实测热电偶温度和冷却水进出口水温差进行验证,计算了优化前后不同方案的窄面铜板和冷却水温度和速度场。对比分析不同方案的铜板热面温度值大小和均匀性后发现,相比于分叉槽结构,圆孔直径D=8 mm和圆孔位置H=26 mm的1孔1槽冷却结构:弯月面铜板倒角热面温度降低幅度最大为14.4~17.6 K;螺栓截面铜板倒角热面温度降低幅度最大为10.9~12.3 K;圆孔内冷却水流速达到8.4 m/s,保证了对倒角面和倒角顶点铜板的冷却;螺栓两侧水槽冷却水流速达10.0 m/s,增强了螺栓周围铜板冷却均匀性。

多级加筋面板受力行为分析及优化

采用三点弯曲实验和有限元仿真方法,对多级加筋面板的变形和破坏进行分析.引入正六边形和内凹六边形两种加筋模式,将具有不同横纵向加筋肋壁厚、圆弧倒角优化的直角边界及二级加筋结构的加筋面板作为研究对象,分析在给定加筋面板几何参数的情况下,横纵向加筋肋壁厚、圆弧倒角优化处理、二级加筋结构对加筋面板结构强度和力学行为的影响.研究表明,加筋面板结构强度随着横纵向加筋肋壁厚的增加而增加,纵向加筋肋壁厚对加筋面板结构影响较大;内凹六边形加筋模式较正六边形加筋模式的加筋面板承载力高;圆弧倒角优化后可以明显改善边角处的应力集中现象、提升加筋面板的结构强度;二级加筋面板的承载能力得到明显提升,且次级加筋层胞元为内凹六边形时提升效果最明显.

倒角结晶器铜板镀层崩边原因分析及控制

针对倒角结晶器窄面铜板镀层崩边问题,从结晶器传热、铜板结构、镀层性能等角度分析原因,提出采用激光熔覆技术对铜板表面进行强化的解决方案,并开展了工业试验进行验证。研究结果表明:铜板角部温度高、镀层厚度大、镀层与铜板热变形差异大、在线调宽状态下铜板侧面清渣不彻底是影响镀层发生崩边的重要原因。采用激光熔覆技术后,倒角窄面铜板的过钢量由5万t提高到10万t以上,当过钢量达到8.7万t时,熔覆层仍未出现角部崩边、剥落及因磨损过大引起的局部露铜现象。

主管道材料微试样液压鼓胀拘束度影响研究

以原始态主管道材料的3种微试样厚度(0.4 mm、0.5 mm和0.6 mm)以及3种倒角半径(0.5 mm、0.8 mm和1.0 mm)为研究对象,进行液压鼓胀试验拘束度影响分析,构建屈服强度、抗拉强度以及液压鼓胀延伸率关联模型,研究屈服强度和抗拉强度的拟合误差以及液压鼓胀延伸率分散性。结果表明,随着微试样厚度的逐步增加,峰值载荷明显增加,而峰值位移普遍降低,但整体曲线趋势变化较小;随着微试样倒角半径的逐步减小,峰值位移明显降低;微试样厚度0.5 mm和倒角半径1.0 mm的试样测试稳定性最佳。

铲钻倒棱刃口几何参数对钻削温度的影响

探究铲钻倒棱几何参数对钻削温度的影响,为铲钻倒棱刃口的参数选择提供参考。通过有限元仿真模拟铲钻钻削过程的温度场得到倒棱角度和倒棱宽度对钻削温度的影响规律。为了验证仿真模拟结果,使用红外热像仪测量钻削过程中切屑温度,并通过光学显微镜观察切屑表面形貌,分析钻削温度随着倒棱刃口几何参数变化的原因。研究结果表明,最高钻削温度区域出现在倒棱面及其附近的前刀面,钻削温度随着倒棱宽度的增大呈现先增大再减小的趋势。随着倒棱角度的增大,钻削温度呈先增大后减小最后再增大的趋势。在设计倒棱刃口时,倒棱宽度应该选择0.1mm<b≤0.3mm,倒棱角度选择10°<γ≤20°,这样可使铲钻刀片具有良好的散热性能。倒棱宽度和倒棱角度的增大加剧了刀—屑的摩擦,导致钻削温度升高,同时也提高了铲钻刀片的散热能力。

基于旋分法圆柱齿轮端面倒棱方法研究

基于生产中圆柱齿轮倒棱的高效率和高经济性等需求,结合旋分加工原理和特点,文章提出了一种基于旋分法端面的倒棱方法。首先,结合旋分加工原理,分析旋分倒棱加工运动,建立齿轮和刀具的运动坐标系,并推导坐标系之间的变换关系;其次,根据选定的初始切削刃和建立的坐标变换关系,在齿轮坐标系中构建初始刃扫面;再次,根据刀具设计原理和刃扫面,构建前刀面得到切削刃和构建后刀面,并建立刀具的三维模型;最后,通过多轴数控加工仿真平台开展了齿轮端面旋分倒棱仿真实验。实验结果表明,使用该方法配合所设计的倒棱刀能够实现齿轮端面齿廓高效倒棱需求。