整体硬质合金球头立铣刀的重磨试验研究

以高速加工的整体硬质合金球头立铣刀的重磨试验为例,介绍了为适应不锈钢的高速加工,铣刀结构参数、涂层而进行的调整,并介绍了铣刀的重磨流程。试切表明:重磨刀具的平均寿命接近新刀。     

四轴数控重磨球头立铣刀端刃的研究

球头铣刀的修磨研究，对于用钝刀具的再利用有着十分重要的作用，如何有效解决球头立铣刀的修磨问题将变得十分迫切。若能在四轴联动机床上实现对球头立铣刀的重新修磨，不仅可以降低成本、减少刀具浪费，提高加工精度与效率，而且能更好地发挥现有机床的作用。本文就球头立铣刀端刃四轴数控重磨的问题进行研究。     

虚拟制造中基于刀具磨损的复杂曲面加工误差补偿

铣削加工过程中刀具的磨损是产生曲面加工误差的重要原始误差,将刀具磨损引起的误差通过建立的误差模型进行定量补偿,是虚拟制造中的一项关键技术。研究了虚拟制造环境下基于球头铣刀磨损的曲面加工误差补偿,建立了与加工参数相关的球头铣刀磨损模型,用以衡量球头铣刀切削刃磨损量,提出球头铣刀铣削加工误差补偿方法,并经实验验证有效。     

球头铣刀曲面多轴加工的刀具接触区半解析建模

刀具接触区界定了切削过程刀具与工件的相互作用范围,是研究切削力学/动力学的基础,复杂曲面加工的刀具接触区往往呈现不规则几何形状且沿曲线刀具轨迹不断变化。针对球头铣刀复杂曲面多轴加工,提出一种刀具接触区半解析建模方法。基于微元离散和刚体旋转变换的思想,将一般复杂曲面加工看成是一系列微小斜平面加工的组合,并且认为球头铣刀斜平面多轴加工的刀具接触区,可由球头铣刀水平面三轴立铣加工的刀具接触区经刚体旋转变换而得。通过将切削余量材料看成是一系列微厚材料薄层的叠加,构建了球头铣刀水平面三轴立铣加工的刀具接触区解析模型,从而建立球头铣刀复杂曲面多轴加工的刀具接触区半解析模型。仿真实例分析了模型的精度和效率,结果表明该半解析模型能够精确高效地描述复杂曲面多轴加工的刀具接触区。     

变密度微织构球头铣刀切削性能多目标优化

为深入研究微织构排列形式对微织构理刀具的抗磨减摩机理的影响,分别从理论、仿真及试验等方面对最优的微织构排布形式进行研究。首先,建立微织构在刀具前刀面的数学模型及仿真模型。其次,通过试验验证仿真结果的准确性。仿真及试验研究均发现,变密度微织构球头铣刀的铣削性能优于均匀分布密度的微织构球头铣刀。最后,运用模糊评价法优选最优的铣削性能的微织构球头铣刀,优化结果表明,两排织构间距先为200 μm,再为150 μm,最后为175 μm的微织构球头铣刀的铣削性能最好。该项研究使刀具具有良好的抗磨减磨性,提高加工效率及被加工工件的表面质量。     

日本黛杰(DIJET)公司精加工用BNM型机夹式球头端铣刀

在模具加工中,粗加工、半精加工已广泛使用机夹式球头铣刀。但是在精加工时,传统的加工方式仍是采用整体硬质合金铣刀。刀具价格高、复磨较难、需重新涂层。复磨后的刀具寿命和精度较原刀具有较大的差距。日本黛杰公司针对这些问题,经过研究和实验,开发出独特的精加工...     

整体叶盘球头鼓锥形铣刀五轴加工技术

鼓形铣刀作为一种高效率的复杂曲面加工刀具,属于非标刀具范畴,其几何参数需要根据加工条件专门定制,目前,定制鼓形铣刀几何参数的有效工具的缺乏是限制其推广应用的主要问题。针对整体叶盘五轴数控加工,提出一种球头鼓锥形铣刀定制方法。该方法通过综合考虑防止干涉的侧倾角、清根加工的球头半径、保证效率的切削行距等约束条件,建立了刀具外轮廓数学模型,编写了刀具参数自动生成的程序。三叶片试件加工仿真和实际切削的结果表明,球头鼓锥形铣刀可以在不降低刀具刚度的条件下,满足叶盘试件加工。与球头铣刀加工相比,其加工效率能够成倍提升,叶片表面质量也有显著提高。     

高速铣削球头立铣刀加工倾角的研究

球头立铣刀铣削曲面时,刀具轴线与工件曲面法线之间的夹角对工件表面质量及刀具寿命有着重要影响,在扼要介绍高速铣削对球头铣刀要求的基础上,通过对球头铣刀刀具轴线和工件加工表面之间的倾角研究,得出了调整刀具和工件之间的加工倾角,有效改善切削条件的策略,对高速铣削参数以及刀具切削路径的优选具有一定的指导意义.     

基于UG模型分析的两刃球头铣刀开发与试验

用球头铣刀加工模具和叶片零件时,球头刃的轮廓度和切削参数决定了零件的精度。采用UG软件对整个球头铣刀的圆弧轮廓度和球头前角进行分析,并结合切削理论找出球头铣刀加工的薄弱点,开发了新结构的球头铣刀,并对模具钢NAK80和叶片材料GH4169进行了切削试验。结果表明:新结构的球头铣刀比原结构更适合模具钢、叶片材料的端铣加工,刀具轮廓精度等级和耐用度更高;在模具加工方面,给出了不同加工精度的切削参数,为模具的高效加工提供参考依据。     

球头铣刀刀具磨损建模与误差补偿

针对刀具磨损度量方式和模型建立的问题,以球头刀具为研究对象,提出球头铣刀刀具磨损的度量方式,建立球头刀具磨损模型.以复映磨损在硬度较软加工材料上的方式测量球头刀具磨损,确定刀具磨损模型系数,给出刀具磨损模型系数确定的具体实现方法.加工试验验证球头刀具磨损度量方式的合理性和所建立刀具磨损模型的正确性,同时针对数控铣削加工中球头铣刀刀具磨损引起的误差提出离线仿真误差补偿算法,给出离线仿真误差补偿算法的具体实现步骤,通过建立的刀具磨损引起的加工误差模型仿真获得加工走刀步的误差.对于误差超差的走刀步,预先修改数控加工(Numerical control,NC)程序,保证实际加工零件满足精度要求.误差补偿验证试验表明所提出的离线仿真误差补偿算法的正确性和有效性.     

曲面铣削过程加工路径对切削力和磨损的影响研究

针对不同走刀路径下的复杂曲面加工过程进行球头铣刀铣削Cr12MoV加工复杂曲面研究,分析不同走刀路径下铣削力和刀具磨损的变化趋势。试验结果表明:通过对比分析直线铣削和曲面铣削过程中的最大未变形切屑厚度,可以得出单周期内曲面铣削的力大于直线铣削过程的力,铣削相同铣削层时环形走刀测得的切削力普遍大于往复走刀测得的切削力;以最小刀具磨损为优化目标,运用方差分析法分析得出不同走刀路径的影响刀具磨损的主次因素,同时利用残差分析方法建立球头铣刀加工复杂曲面刀具磨损预测模型,并通过试验进行验证。     

Design and fabrication of a new micro ball-end mill with conical flank face

Micro ball-end milling is an efficient method for the fabrication of micro lens array molds. However, it is difficult to meet the machining quality of micro dimple molds due to the wear and breakage of the milling cutter, which presents large challenges for designing geometric structure and edge strength of micro ball-end mills. In this study, a new configuration of a micro ball-end mill for micro dimple milling is designed and named the micro conical surface ball-end mill. The cutting edge is formed by intersecting the conical surface and the inclined plane. A practical grinding method is proposed based on the kinematic principle of the six-axis computer numerical control (CNC) grinding machine for micro conical surface ball-end mills and is validated by grinding simulations and experiments. Micro dimple milling experiments are conducted on the hardened die steel H13 to investigate the cutting performance of the mill. The milling force, the micro dimple roundness error, and the tool wear morphology are observed and analyzed. The results show that the radial milling force is more stable and the wear resistance is improved for the micro conical surface ball-end mill compared to the traditional micro spiral blade ball-end mill. Therefore, a more stable roundness at the entrance hole of the micro dimple can be obtained by using this design after a number of micro dimples have been milled.     

Generating efficient tool paths from point cloud data via machining area segmentation

This paper presents a method of generating efficient three-axis ball-end milling tool paths directly from point cloud data. The primary objective is to achieve high efficiency in the machining of free-form surface geometry having isolated complex machining area. The high machining efficiency is attained by segmenting the entire machining domain into distinct areas according to the geometric complexity of the data points and by using cutters of different sizes for the segmented machining areas. An iterative numerical procedure is derived to determine the critical complexity that separates the data points with higher complexity (the complex points) from those with lower complexity (the non-complex points). A larger and more efficient ball-end mill is used to machine the area defined by the non-complex points. The gouging condition of all the data points is then evaluated with respect to the given ball-end mill. The isolated complex machining area is established by enclosing both the complex points and the gouge points. The smaller and gouge-free ball-end mill for the isolated complex machining area is subsequently selected from the standard commercial cutter series. Implementation of the presented method clearly demonstrates the high efficiency of the generated tool paths.     

Characteristics of Inclined Planes According to the Variations of Cutting Direction in High-Speed Ball-End Milling

The recent developments of the manufacturing industry require the machining of freeform surfaces using a ball-end mill. The ball-end mill is geometrically complex. For this reason, there are frequent changes of the contact point between a workpiece and a tool, which changes the machining characteristics when machining a freeform surface. In this study, a comparative evaluation of cutting characteristics will be made for a workpiece with inclined planes at angles of 15°,30°, and 45° each using four possible tool paths in down cutting. Then, tool life will be evaluated for heat-treatment materials of high hardness before obtaining the optimal tool path, which makes machining stable and improves tool life.     

曲面加工残留高度问题的解决方案

如何保证曲面加工精度,特别是高度方向残留材料的去除,成为众多企业关注的重点。球头刀是曲面加工的主要工具,研究了球头刀在加工曲面过程中的正确转速计算以及高度方向残留材料的去除,进行了详细的分析并推导出相应的理论计算公式,能够较好的解决曲面加工过程中残留沟纹高度的精度问题。     

Cutting force prediction for ball-end mills with non-horizontal and rotational cutting motions

Accurate cutting force prediction is essential to precision machining operations as cutting force is a process variable that directly relates to machining quality and efficiency. This paper presents an improved mechanistic cutting force model for multi-axis ball-end milling. Multi-axis ball-end milling is mainly used for sculptured surface machining where non-horizontal (upward and downward) and rotational cutting tool motions are common. Unlike the existing research studies, the present work attempts to explicitly consider the effect of the 3D cutting motions of the ball-end mill on the cutting forces. The main feature of the present work is thus the proposed generalized concept of characterizing the undeformed chip thickness for 3D cutter movements. The proposed concept evaluates the undeformed chip thickness of an engaged cutting element in the principal normal direction of its 3D trochoidal trajectory. This concept is unique and it leads to the first cutting force model that specifically applies to non-horizontal and rotational cutting tool motions. The resulting cutting force model has been validated experimentally with extensive verification test cuts consisting of horizontal, non-horizontal, and rotational cutting motions of a ball-end mill.     

基于复映测量的球头刀具磨损数据处理及其软件开发

在铣削加工中,刀具磨损对产品加工质量有重要的影响,以球头刀具磨损为研究对象,为了建立刀具磨损模型,采用复映测量手段获取刀具磨损,在复映测量获得刀具磨损的过程,针对复印测量的球头铣削刀具磨损数据提出了数据处理的方法,并以Visual C++为开发平台实现了基于复映测量的刀具磨损数据处理模块,为基于复映测量的刀具磨损建模提供了基础,所提出的刀具磨损数据处理方法可有效对刀具磨损数据进行分析建立刀具磨损模型。     

考虑模态耦合的球头铣刀颤振稳定域建模方法

球头铣刀广泛应用于曲面加工中,因此构造出针对球头铣刀的颤振稳定域叶瓣图意义重大。利用精细积分法对铣削系统二阶动力学方程进行时域数值求解,由切削刃与切触区域不同时刻的关系,确定出时域数值求解方程中所需要的刀刃瞬时切削部位,通过Floquet定理获得了高精度的颤振稳定域叶瓣图,并在三轴数控机床上进行了正确性试验验证。试验结果与预测结果相一致,表明所提供的方法能够为球头铣刀实现无颤振切削加工提供有力的技术支撑。     

球头铣刀的设计与仿真

提出了一种应用计算机绘图软件和OpenGL设计球头铣刀的方法,建立了一种球头铣刀的前刀面与后刀面的数学模型.通过OpenGL建模,建立了仿真处理系统和球头铣刀的螺旋柱面、球头(包括前刀面、排屑槽、主后刀面和副后刀面)和砂轮的三维仿真模型.应用数学模型和VC++软件平台,并利用OpenGL控制界面实现了设计结果的可视化及...