NC code generation for laser assisted turn-mill of various type of clovers and square section members

Laser assisted turning （LAT） is one of the advanced machining technologies, which uses laser power to heat the surface of a workpiece before the material is removed. It has several advantages of low manufacturing costs, high productivity and high qualities to machine difficult-to-cut materials such as silicon nitride, muUite, zirconia and Ni. A large part of studies on LAT have been focused on a round bar. With increasing demands for high quality products and high performance engineering system, the researches on LAT for clover and square section members are necessary. But, these workpieces are impossible to be machined on conventional CNC lathe and to generate NC code with current CAM softwares. As a basic research for combining LAT with a tilting index table type 5-axis machining center, i.e. laser assisted turn-mill, a new method is suggested to generate NC code that can process various types of clover and square section members through development of C＋＋ program.

Experimental study on chatter of micro-miniature turn-milling

A chatter experiment of micro-miniature turn-milling was carried out in this paper. In or- der to reduce the effect that the natural frequencies of workpieces brought to the chatter experiments of micro-miniature turn-milling, both positive and negative cone-shape workpieces were used . The chatter frequency of micro-miniature turn-milling process was obtained by the sampling and analyzing systems. Then by applying excitation experiments to the workpiece system and tool system respec- tively, the natural frequencies of these two systems were obtained. By comparing chatter frequency of micro-miniature turn-milling process with the natural frequencies of workpiece system and tool system, we found that chatter frequency of micro-miniature turn-milUng was close to the natural fre- quency of the low stiffness vibration body in the machine tool system. The funding could be useful for optimizing the structure of machine-tool and designing the machining process.

Vector modeling and track simulation in axial turn-milling motion

Through vector analysis the kinetic vector model is built in a machining cylinder surface through axial turn-milling. When building a kinetic vector model in the machining field, machining through axial turn-milling and using equilateral triangles and square prism surfaces, the kinetic vector model is given any equilateral polygon prismic surface. Kinetic tracks are simulated through these kinetic models respectively, thus it can be seen that the axial turn-milling is a very effective method in manufacturing any equilateral, polygon, prismic surface.

Research on Machined Surface Veins Based on Turn-milling Technology

Turn-milling which history dates from the end of the 20th century is one of the advanced metal cutting technologies. It could precisely machine hard materials as an alternative to turning for certain limitations. A series of orthogonal turn-milling surface veins experiments have been done on the turn-milling machining center by machining aluminum alloy,and then the nexus between the surface veins and the cutting regimes is studied. The mathematical model for surface vein direction angle is established,also the forming mechanics of surface vein direction is analyzed. Its variety regulation presents decreasing trend with as axial feed and cutter rotary speed increasing. For different eccentric distance of orthogonal turn-milling,the surface veins are different.

Research on the cutting performance and the wear mechanism of the cermet cutter in high speed turn-milling

When machining D60 steel by high speed turn-milling under the different cooling and lubricating conditions, the cutting performance and the wear mechanism of the cermet cutter are researched. With water soluble cooling fluid, the wear performance of the cermet cutter is bad, and does not adapt to the requirements of machining. However, when machining D60 by high speed turn-milling is under dry conditions, the wearing performance of the cermet cutter is very good and the cutting time lasts almost 3 hours. The wear mechanism of the cermet cutter under the water soluble cooling fluid is different from the dry condition. With the water soluble cooling fluid, a great deal of little chap units are formed since high frequency alternates heat stress. The crash and desquamate of these chap units is the main cause of the cutter wearing. Under dry cutting conditions, it is the main cause of cermet cutter wear in the felting phase intenerating causing rigid phase grains to fall.

Experimental investigation of cutting parameters in machining of 100Cr6 with tangential turn-milling method

The turn-milling methods for machining oper- ation have been developed to increase efficiency of con- ventional machines recently. These methods are used especially by coupling some apparatuses on the computer numerical control （CNC） machine to decrease the pro- duction time and machine costs, ensure the maximum production and increase the quality of machining. In this study, 100Cr6 bearing steel extensively used in industry has been machined by tangential turn-milling method. This paper presents an approach for optimization of the effects of the cutting parameters including cutter speed, workpiece speed, axial feed rate, and depth of cut on the surface roughness in the machining of 100Cr6 steel with tangential turn-milling method by using genetic algorithm （GA）. Tangential turning-milling method has been determined to have optimum effects of cutting parameters on the machining of 100Cr6 steel. The experimental results show that the surface roughness quality is close to that of grinding process.

Machinability of damage-tolerant titanium alloy in orthogonal turn-milling

The damage-tolerant titanium alloy TC21 is used extensively in important parts of advanced aircraft because of its high strength and durability. However, cutting TC21 entails problems, such as high cutting temperature, high tool tip stress, rapid tool wear, and difficulty guaranteeing processing quality. Orthogonal turn-milling can be used to solve these problems. In this study, the machinability of TC21 in orthogonal turn-milling is investigated experimentally to optimize the cutting parameters of orthogonal turn-milling and improve the machining efficiency, tool life, and machining quality of TC21. The mechanism of the effect of turn-milling parameters on tool life is discussed, the relationship between each parameter and tool life is analyzed, and the failure process of a TiAlN-coated tool in turn-milling is explored. Experiments are conducted on the integrity of the machined surface (surface roughness, metallographic structure, and work hardening) by turn-milling, and how the parameters influence such integrity is analyzed. Then, reasonable cutting parameters for TC21 in orthogonal turn-milling are recommended. This study provides strong guidance for exploring the machinability of difficult-to-cut-materials in orthogonal turn-milling and improves the applicability of orthogonal turn-milling for such materials.

Variable eccentric distance-based tool path generation for orthogonal turn-milling

This study proposes an algorithm for max- imizing strip width in orthogonal tum-miUing based on variable eccentric distance. The machining error model is first established based on the local cutting profile at the contact line. The influencing factors of the strip width are then investigated to analyze their features and determine an optimizing strategy. The optimized model for maximum machining strip width is formulated by adopting a variable eccentric distance. Hausdorff distance and Fr6chet distance are introduced in this study to implement the constraint function of the machining error in the optimized model. The computing procedure is subsequently provided. Simulations and experiments have been conducted to verify the effectiveness of the proposed algorithm.

切向车铣18CrNiMo7-6钢V形缺口表面三维形貌研究

疲劳试样的缺口加工一直是一个亟需解决的难题。提出一种全新的切向车铣加工缺口工艺,通过理论与试验结合的方法探究了切向车铣对V形缺口表面形貌的影响规律。结果表明:在不同的工艺参数下,切向车铣V形缺口底部会呈现出不同的加工纹理方向,提出的理论公式计算出的纹理方向与工件轴线的夹角与实际结果误差很小;缺口底部三维表面粗糙度R_(a)随着铣刀转速n_(c)的升高而减小,随着工件转速n_(w)的升高而变大,随着每齿进给量f_(z)的增加先减小后增大;得到表面粗糙度最优参数组合为n_(c)=6000 r/min,n_(w)=100 r/min,f_(z)=0.0375μm,在此切削参数组合下得到的V形缺口表面粗糙度R_(a)可达到0.075μm。

基于非参数回归响应面法的高精车铣复合机床床身多目标联合优化设计

精密化是机械加工领域追求的目标,数控车铣复合机床作为高端机械加工装备,其床身的动静态特性对机床加工精度有显著影响。针对当前床身结构优化方法效率低、效果差的问题,文章提出一种非参数响应面法的多目标联合优化方案。该方案首先根据有限元分析结果挑选出模型的优化尺寸,并将床身质量、最大形变、一阶固有频率作为联合优化目标;通过建立参数试验对尺寸进行敏感性分析,精准选出敏感性较大尺寸;基于非参数回归法建立响应面,导入所选尺寸,计算试验样本的响应值,建立非参数回归响应面优化模型,并采用多目标遗传算法找出最优设计方案。最优方案优化结果为:机床床身最大形变降低约14.667%,一阶固有频率提升约3.187%,质量降低约1.208%。结果表明该优化方案能够高效提升机床床身动静态特性,为机床优化设计提供理论依据。

正交车铣大直径钛合金无缝管径向切削力的研究

大直径钛合金无缝管属于大型薄壁件,目前主要采用车削进行外圆加工,较大的径向切削力容易引起工件变形。正交车铣加工外圆表面时径向切削力相对较小,是一种能更好加工这类零件的新方法。通过三因素三水平正交仿真试验,研究采用偏心正交车铣加工大直径钛合金无缝管外圆时,切削参数对径向切削力的影响,建立了径向切削力的经验公式。结果表明,切削参数对径向切削力影响的大小顺序为a_(p)>f_(z)>v_(c),可通过适当增加每齿进给量提高切削加工的效率。

基于成组技术的滚刀复合加工零编程系统开发

针对齿轮滚刀个性化、小批量的需求现状和多工序、低效率的加工现状,利用成组技术原理对齿轮滚刀进行分类,通过分析现存滚刀加工工艺设计车铣复合加工工艺,提出基于成组技术零编程实现滚刀的半成品加工。以整体式滚刀为研究对象,车铣复合机床BHR700V为平台,设计各工序的结构和工艺参数化变量,实现各工序的参数化编程,在西门子SINUMERIK 840d数控系统上开发出齿轮滚刀的定制化人机界面,并在车铣复合机床BHR700V上成功用于滚刀半成品加工。

数控车铣中心铣削加工工艺的应用分析

数控车铣中心是一种用于机械工程领域的工艺试验仪器,以车为主,以铣为辅助,相当于一台数控车床和一台加工中心的复合,其优势在于作业过程中可保持稳定、精密、快速加工,广泛应用于航空航天、汽车制造、模具制造等领域。本文以数控车铣中心铣削加工工艺应用为研究对象对其进行分析和探讨,首先介绍了数控车铣分类,然后分析了数控车铣中心铣削加工工艺的应用各要点,最后提出了提升数控铣削加工质量的措施,以期能够为促进铣削加工工艺发展提供有效参考。

基于1+X证书制度的中职课程设计路径——以《数控车铣加工》课程为例

1+X证书制度是衔接职业教育与企业工作岗位的桥梁,推动课程内容与企业工作任务融通,教学标准与岗位标准融合,教学过程与工作过程对接,促进中职学校教师、教材、教法改革,对提升学生综合职业能力有深远的意义和影响。以数控技术应用专业为例,分析1+X证书制度对《数控车铣加工》课程设计,完善“岗课赛证”综合育人机制,培养适应时代发展的高技能专业人才。

航空发动机鼠笼弹支轴承弹性支承内径面的工艺改进

针对某航空发动机鼠笼弹支轴承弹性支承内径面先热处理后铣削工艺加工精度及效率低的问题,采用先硬车后铣削加工,并对车削刀具结构进行改进以满足加工需求。工艺改进后的弹性支承内径面加工精度及效率得到了明显提升,且降低了加工成本。

基于UG和VERICUT的牙轮钻头牙轮数控加工仿真研究

牙轮钻头作为石油钻井作业中重要的破岩工具,其加工质量成为了钻头使用寿命长短的重要因素。为了解决牙轮零件加工精度要求高、工序繁多,且需多次装夹等问题,对牙轮零件整体加工工艺进行优化改进。通过UG软件对牙轮整体加工进行工艺规划和数控编程,模拟加工仿真刀路运动轨迹。基于VERICUT软件建立XYZBC五轴车铣复合数控机床运动学模型、开发控制系统、创建刀具库并搭建虚拟仿真平台,模拟仿真零件的实际加工过程,验证和优化加工程序和加工工艺。将加工结果与实际牙轮零件进行分析比较。结果表明:与传统工艺相比,优化后的工艺一次装夹即可完成牙轮零件的一体式加工,大幅提高了牙轮的加工效率,使牙轮产品加工质量保持稳定,牙轮的寿命也得到了相应改善。

四轴车铣复合加工中心NX后处理程序开发

提供了一种基于NX后处理构造器的四轴车铣复合加工中心后处理程序开发方法,以机床操作手册为指导,结合现场的实际操作需求,完成四轴车铣复合加工中心的后处理程序制作,并且通过了实际的切削测试。

紫铜小锥度锥形内腔类零件加工工艺研究

为加工出小锥度锥形类结构,基于车削、铣削加工原理,提出车削和铣削相结合的加工方法。首先建立车削锥形内腔零件数学模型,分析车削内形机理;依据球头铣刀刀刃排布数学模型,建立球头铣刀铣削锥形内腔的运动轨迹,分析小锥度锥形内腔结构成形机理以及该方案的可行性,并得出锥形内腔车削深度与车刀直径、锥形内腔开口半径、锥形内腔开口角度有关的结论。在此基础之上,通过车削和铣削相结合的方法加工出了小锥度锥形内腔类结构。

基于VERICUT的数控车铣加工中心仿真技术

数控车铣加工中心是一种集车床和铣床功能于一体的高效加工设备,广泛应用于制造业。为了提高加工效率和减少加工误差,首先介绍数控车铣加工中心的基本原理,分析其在制造业中的重要性。然后,针对数控车铣加工中心的复杂加工过程,介绍VERICUT仿真软件的功能,重点探讨基于VERICUT的数控车铣加工中心仿真技术的研究方法,通过建立数学模型和仿真算法,将加工过程中的各种因素考虑在内,实现对加工过程的全面仿真。经过实践证明,通过应用仿真技术,可以有效提高加工效率,降低加工成本和风险。

低压涡轮转子WFL车铣复合加工工艺研究

针对低压涡轮转子现存问题,在数控加工工艺性分析的基础上,对车铣复合数控加工关键技术进行相关研究。首先,对低压涡轮转子的工艺性进行分析;其次,研究加工中的难点;最后,对于加工中出现的问题给出相应的解决方案,包括程序优化、工装改进、机加工过程中的变形控制等,以期为相关人员提供参考与借鉴。