低碳低合金钢在16.8m3电铲铲齿上的应用

根据德兴铜矿实际工况条件,结合具体的铲齿结构,设计了水淬低碳低合金钢铲齿,并在16.8M3电铲上进行了装机试验,结果表明,试验铲齿的使用寿命和岩石的采剥量均比现场使用的低合金钢铲齿提高一倍,取得了良好的使用效果.     

基于PMOPSO方法的H型铲齿凸轮优化设计

给出一种H型铲齿凸轮的标准设计方法,用于解决多升程H型铲齿凸轮的优化设计问题。针对传统铲齿凸轮存在的过渡点冲击问题,提出基于H型凸轮从动件运动规律的铲齿凸轮设计方案。以凸轮面积为设计目标函数,以从动件的偏置量和初始位移为设计变量,在凸轮一般设计准则的基础上,考虑理论廓线曲率范围和压力角分布的约束条件,建立H型铲齿凸轮的优化设计模型。多升程H型铲齿凸轮的优化设计问题具有约束条件多、非线性强和计算复杂度高的特点,将多项式变异算子和标准粒子群优化结合,提出多项式变异粒子群优化方法。以此优化方法为基础,通过构造罚函数处理设计约束,分别求解三升程和四升程的H型铲齿凸轮优化设计问题。计算结果表明,提出的标准设计方法可显著降低多升程H型铲齿凸轮的工作轮廓面积,使铲削机构更加紧凑。     

节子木材成形铣刀的研究

针对节子木材的加工研制开发成形铣刀。分析节子木材切削机理,应用国内外锯切新技术和成形刀具设计的最新成果,成功研制出了带锯齿、大前角、锯齿有不同交互变化倾角的薄锯路圆锯片,多块组合拼装,锯刃分布沿刀轴呈螺旋状的新型成形铣刀。该刀具已投入使用,切削性能良好。     

曲线齿线圆柱齿轮啮合数学模型

参照圆弧齿线圆柱齿轮齿面方程的推导方法以及齿面组成特点,介绍了一类曲线齿线圆柱齿轮的齿面组成特点.采用齿轮啮合原理中的单参数曲面包络方法,运用坐标变换推导了曲线齿线圆柱齿轮的数学方程和共轭齿面方程的一般形式.以圆弧齿线圆柱齿轮的齿面方程推导为例,推导了圆弧齿线圆柱齿轮的空间啮合数学模型,并采用UG建模软件建立了圆弧齿线圆柱齿轮的3D模型,验证了该方法的正确性.研究结果为进一步开展新型齿线的设计、新型曲线齿线圆柱齿轮传动研究提供了理论基础.     

不等齿距端铣刀的减振机理

本文根据切削理论及端铣过程的几何关系，提出了单齿和多齿端铣刀的铣削力模型，对不等齿距端铣刀的实质进行了分析，论述了不等齿距端铣刀的减振机理     

基于CAXA电子图板齿辊立式加工数控程序设计

生产中,我们经常会遇到一些在卧式机床加工而没有专用成形刀具,但又急需加工的零件。利用现有设备和刀具在立式数控机床加工齿辊是我们本次探讨的话题。本文采用CAXA作图方法采集程序数据,用立铣刀在立式数控机床上加工齿辊零件做一详述。     

双主轴行星式弧齿锥齿轮指状铣刀盘结构方案设计研究

为了实现硬齿面弧齿锥齿轮的铣削，提高超人规格弧齿锥齿轮寿命，构造了一个双主轴行星式弧齿锥齿轮指状铣刀盘方案设计系统。设计人员在结构设计时，首先要对新的设计问题进行分析，计算并审核零部件的结构参数，加工与检测，最终形成双主轴行星式弧齿锥齿轮指状铣刀盘的结构设计方案。同时。为了帮助企业立即实现盈利，运用现有的机床进行改造，设计方案规范化，提高企业竞争力。     

基于改进Mask Scoring R-CNN的铲齿磨损检测研究

为了实现在电铲工作过程中对铲齿磨损进行实时检测，防止因铲齿磨损而影响电铲开采效率，提出了一种基于改进Mask Scoring R-CNN（region convolutional neural network，区域卷积神经网络）的铲齿实例分割模型。首先，以ResNet-101（residual network， 残差网络）和改进的FPN（feature pyramid networks，特征金字塔网络）作为主干网络，提取高、低特征层的语义信息和细节特征并融合，结合ROI Align层对局部特征层进行裁剪和归一化处理，以完成目标检测与实例分割；然后，基于获取的铲齿分割效果图以及二值化掩码图形信息，计算实例分割后图像中铲齿部分的像素面积，以判断其磨损情况。结果表明，以ResNet-101和改进FPN为主干网络的铲齿实例分割模型在测试集上的平均像素精度为90.76%，平均交并比为83.62%，相比于以ResNet-101和传统FPN为主干网络的实例分割模型分别提升了1.18%和1.21%。在电铲采掘工作现场进行8次铲齿磨损检测实验，检测到的每颗铲齿的磨损程度波动幅度均小于2%，均方差为0.7左右，说明所提出的实例分割模型对铲齿有较好的分割效果和稳定性，基本满足磨损检测要求。研究结果可为铲齿磨损状态的智能化检测提供新思路。     

直齿锥齿轮参数化三维建模方法

介绍了在AutoCAD 环境下,用Autolisp 语言编程在计算机上实现直齿锥齿轮参数化三维建模的方法.程序设计是基于齿轮范成法切齿原理.使用该研究成果,只需加载Autolisp程序,输入模数、齿数、齿轮分度圆锥角等参数,便可以自动生成刀具和轮坯,齿轮的轮齿由刀具与轮坯间的相对滚切而形成.程序中还设计了轴、孔及键槽等结构,最后生成按指定参数的标准直齿锥齿轮模型.     

泛曲线齿锥齿轮的创新设计与应用的二次开发

曲线齿锥齿轮和准双曲面齿轮（统称为"泛曲线齿锥齿轮"）,是一种十分复杂而应用越来越广泛的传动装置。在设计上为了避免改变轴交角,而采用"零"变位传动（x1+x2=0）设计的齿形制,至今已在各国工业上通用近百年。文章介绍一种"非零"变位传动（x1+x2≠0）设计而又保持轴交角不变的创新齿形制。为了满足生产提出的要求,进行了二次开发。经过第二次创新,能在普通锥齿轮加工机床和刀具上切齿,故极易推广。近12年来,已成功地在工程机械、军品、立式机床、机车、船艇、油田、采煤、水泥等机械上采用,取得高综合强度、高可靠性、长寿命、小体积、低噪声、广泛适应性等优点,可取代（或覆盖）全部以美国Gleason为代表的零传动齿制设计的产品,还可实现某些Gleason所达不到的技术要求,故有广泛的应用前景。     

Investigation of logarithmic spiral nanoantennas at optical frequencies

The first study is reported of a logarithmic spiral antenna in the optical frequency range. Using the finite integration technique, we investigated the spectral and radiation properties of a logarithmic spiral nanoantenna and a complementary structure made of thin gold film. A comparison is made with results for an Archimedean spiral nanoantenna. Such nanoantennas can exhibit broadband behavior that is independent of polarization. Two prominent features of logarithmic spiral nanoantennas are highly directional far field emission and perfectly circularly polarized radiation when excited by a linearly polarized source. The logarithmic spiral nanoantenna promises potential advantages over Archimedean spirals and could be harnessed for several applications in nanophotonics and allied areas.     

Parametric relationship between hypoid gear teeth and accurate face-milling cutter

The cutter systems of hypoid gear cutting machines contain groups of inside and outside blades. In these cutter systems, the side cutting edges of the blades machine the convex and concave gear teeth while rotating about the cutter rotation axis. The side cutting edges lay on the rake face formed through the blade, rake, and relief angles; hence, the normal cross-section of the cutter swept surface forms hyperboloid gear teeth. Using the accurate geometry of the cutter system, a relationship between the pressure and spiral angles of the gear tooth and the parameters of the cutter system is developed for the FORMAT machining of a hypoid gear. A new parameterization of the gear tooth surfaces is introduced to determine these angles for the accurate gear tooth by the accurate cutter system. A numerical example with different cutter systems and blade parameters is presented, demonstrating the effects of rake and relief angles over the pressure and spiral angles on mean point projections and gear tooth surface. Finally, the change in pressure and spiral angles with respect to the rake and relief angles are plotted, and the results are analyzed. Finally, it is concluded that the pressure and spiral angles are changed up to a few seconds of a degree in the operating area of the tooth with the change in the back and side rake angles. The side relief angle exhibited little or no effect over the geometry of the gear tooth.The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-019-00286-x     

成型砂轮廓形设计的CAD法

将作图法和计算法相结合,提出成型砂轮廓形的CAD设计方法。该方法以啮合原理为根据,采用反求设计的思路;通过做一系列垂直于砂轮轴线的截面,得到相应的砂轮与螺旋槽的接触点,连接这些接触点得到接触线,将接触线绕砂轮轴线旋转360°,即是成型砂轮的廓形。该方法具有简单直观、结果准确的特点。以球头铣刀螺旋槽的成型磨削为实例,对用CAD法设计成型砂轮的过程进行说明。该方法可用于各种按展成原理进行加工的成型工具的轮廓设计。     

基于UG NX6.0的整体叶轮的多轴加工技术

叶轮加工是当今多轴联动数控加工最常见的实例,也是数控加工的难点之一.本文从实际出发,使用UG/CAM五坐标编程系统对整体式叶轮进行数控编程,采用插值方式对刀轴矢量进行匀化处理,采用SWARF方法对叶片进行精加工,同时合理控制进退刀,实现了整体叶轮叶片高质量无干涉的五坐标螺旋铣削加工刀位点轨迹生成.为复杂产品的造型和数控加工提供了设计思路和方法,也给其他类型叶轮的设计与加工提供了参考方案.     

复杂零件数控编程KBE系统广义知识库应用研究

在分析数控编程KBE系统各模块相互联系的基础上,构建了基于KBE的复杂零件数控编程系统功能架构和广义知识库结构模型．综合数据库技术和知识库理论,建立了数控编程广义知识库系统．阐述了广义知识库的设计思想,给出了数控编程广义知识库与UG CAD／CAM应用接口实现的技术路线．并以企业需求为背景,在知识驱动型制造平台（UG CAD／CAM）上,利用VC＋＋6．0和UG／Open,将广义知识库系统和UGCAD／CAM无缝集成,实现了KBE和UG CAD／CAM系统的融合,开发了复杂零件数控编程KBE系统,验证了课题研究的可行性和实用性．     

沿螺线轨道飞行的太阳帆航天器姿态被动控制研究

太阳帆是一种新型航天器,它可以借助太阳光压作为动力而自身无需携带大量的燃料,因而被设计运用于星际航行和深空探测。其中,用于星际航行的对数螺线轨道引起了研究者的兴趣。这样的飞行任务中,要求太阳帆的姿态与太阳光线方向成一个固定的角度。常见的对称的太阳帆平板模型不能被动的保持满足上述要求的姿态。该文利用不对称的太阳帆设计来实现被动的姿态控制,并利用轨道、姿态耦合的动力学模型进行仿真。结果表明:在空间干扰微弱的环境条件下,可以实现被动姿态稳定。     

Optimal cutter size determination for 2½-axis finish machining of NURBS profile parts

A curve model of non-uniform rational B-spline (NURBS) has been widely adopted in mainstream CAD/CAM software systems to design complicated geometries of mechanical parts, for example, the curved profiles of pockets, sides, and islands. NURBS profile parts (the profiles include NURBS curves for pockets and islands) are produced in 2½-axis rough and finish machining. In rough machining of the parts, several end-mills with different sizes are employed for high cutting efficiency, and in finish machining, a single end-mill is usually used to cut along the profiles for high surface quality. To accurately produce the geometries with NURBS curves in finish machining, the cutter size should be optimised in order to eliminate gouging and save machining time. Although this topic has been a research focus for a decade, optimal cutter size determination still remains as a technical challenge. To rise to this challenge, our work proposes a new approach to determining the largest allowable size for the cutter to move along all the profiles (including NURBS curves) in 2½-axis finish machining without global and local gouging. The salient feature of this approach is that an original model of the cutter size is formulated and an effective solver–the particle swarm optimisation method–is employed to compute the largest allowable cutter size. This intelligent approach is more efficient and accurate than the conventional computational method based on the test examples in this work. It can also be applied to global and local gouging detection for NURBS profile machining. Our research work has great potential to advance CNC machining techniques.     

成型铣刀刀刃曲线的数学分析

本文分析了成型铣刀刀刃曲线的几何性质，推导出它的数学方程，求取铣刀上圆盘刀片中心坐标，为成型铣刀的计算机辅助设计奠定了理论基础。     

An Analytical Approach to Optimize NC Tool Path Planning for Face Milling Flat Convex Polygonal Surfaces

CAD/CAM systems currently generate the tool cutter path for many NC operations. However no mathematical model is available for computing an optimal tool cutter path for face milling. By utilizing such a model, the minimum length of cut can be identified for face milling flat surfaces. In this paper, the authors present an analytical procedure from which the optimal cutting path may be derived.     

Cutter size optimisation and interference-free tool path generation for five-axis flank milling of centrifugal impellers

Strategies for cutter size optimisation and interference-free tool path generation are proposed for five-axis flank milling of centrifugal impellers. To increase the material removal rate and provide a stronger tool shank during flank milling, the cutter size is first maximised under a set of geometric constraints. The tool path is then globally optimised in accordance with the minimum zone criterion for the determined optimal cutter size. Aside from the local interference of the cutter with the design surface, the global interferences with the hub surface and the adjacent blade surface are also considered in the optimisation models. Interference is indicated by the signed distance from the sampled point on the blade surface to the tool envelope surface. This distance is calculated without constructing the envelope surface. On the basis of the differential property of the distance function, we choose a sequential linear programming method in implementing the optimisations. This approach applies to generic rotary cutters, such as cylindrical and conical tools. Simulations are conducted to obtain the optimal cutter size and generate an interference-free tool path for a practical impeller. Simultaneously, a software module that can generate tool envelope surfaces and verify geometric errors is used to validate the proposed method.