异形链条附板直线进给靠模仿形铣工装设计

靠模仿形铣削加工是成型轮廓加工方法之一.设计制造了直线进给靠模仿形铣滑台,根据不同的工件轮廓设计专用靠模轨迹槽和刀具系统、对刀系统、工件定位装夹系统.必须使刀具中心轨迹与靠模轨迹槽中心形状完全相同并方向一致,同时经过对刀和工件定位,使刀具、工件轮廓、靠模轨迹槽有正确的相对位置.     

典型复杂型面模件高效数控加工策略

以垫片模下模镶件为研究对象,重点研究了数控加工工艺的优化问题,旨在提高模具型腔数控加工效率、加工质量、降低刀具磨损,实施高效的数控加工策略;提出了模具型腔粗铣加工刀具组合方法,进行了粗铣加工走刀方式对比分析,针对深孔、薄壁、复杂轮廓曲面等难加工部分制定了相应的加工策略,优化了加工工艺,使用UG CAM进行编程,生成了高效的加工刀路,进行了加工仿真,并自行开发了后处理器,在华中文控铣床上加工出试样,该策略提高了加工效率、产生了良好的经济效益.     

浅谈数控铣削中刀具半径补偿的功能及应用

通过分析数控铣削加工中合理建立和灵活运用刀具半径补偿对零件进行编程与加工的过程,说明可以根据工件轮廓尺寸编制加工程序,以及预先存放在内存中的刀具中心偏移量,系统能自动计算刀具中心轨迹,并控制刀具进行加工;在加工过程中,只需根据工件坐标系的位置进行对刀,便可使用同一程序而对零件实现粗、精加工,以简化编程,并提高加工品质。     

倒角几何特征数控编程

对倒角几何特征在UG数控编程中涉及的常规倒角刀具、自定义刀具,从创建到使用进行了归纳,对倒角几何特征涉及的面铣、平面铣、固定轮廓铣操作参数设置进行了详细剖析。固定轮廓铣边界驱动可作为平面/空间棱边倒角加工的首选方案,并通过一个空间倒角案例展示了固定轮廓铣边界驱动操作在倒角编程中的通用与高效性。     

三轴数控侧铣空间刀具半径补偿算法

通过深入分析三轴数控侧铣加工的特点,利用几何平面投影原理,采用平面轮廓刀具半径补偿算法推导的类似方法,建立三轴数控侧铣加工的空间刀具半径补偿算法.将三轴数控侧铣加工的空间刀具半径补偿归纳为三种转接过渡类型处理,通过加工平面的投影相交求出空间两相邻程序段的过渡转接点坐标分量x、y,然后通过逆投影计算转接点的第三分量z,从而推导出各类型转接点的坐标计算公式.基于UG平台编写了三轴数控侧铣刀具补偿仿真软件,模拟和铣削加工实例结果表明所建立的三轴数控侧铣加工空间刀具半径补偿算法正确有效.基于该算法的空间刀具半径补偿G指令将可避免由于刀具磨损和刀具更换导致的三轴侧铣数控代码重生成.     

数控铣削加工中的刀具半径补偿过切现象分析

零件轮廓数控铣削手工编程时,通常采用刀具半径补偿的方法。按照工件轮廓编程,通过改变刀具半径补偿值来控制零件加工尺寸,实现同一程序、同一刀具进行同一零件轮廓的粗、精加工。但在应用刀具半径补偿编程加工中,时常会出现过切或过切报警,需要正确分析和处理才能正确使用刀具半径补偿。文中将过切现象分为3类：与切入切出路径有关的过切现象、与刀具半径补偿值大小有关的过切现象和与刀具移动量有关的过切现象,针对每类编程加工中出现的过切或过切报警现象进行了分析。     

THM6350精密卧式加工中心由宁江机床集团股份有限公司生产制造

本机床为四轴三联动或四轴联动卧式加工中心,机床在一次装夹后,可完成铣、钻、镗、铰、攻丝和轮廓的粗、精加工、当机床配置六工位托盘的工件自动交换装置(即APC),工件检测系统、刀具检测系统以及相应的数控系统,可进行长时间无人看管运行的混流加工(即柔性加工单元)。     

在数控线切割机床上加工凸轮

我厂C1336自动车床使用的凸轮,一直是用图解法画出凸轮轮廓曲线后,按线粗铣,然后手工修磨的方法加工。由于加工过程中凸轮升高半径不便测量,致使加工后的凸轮轮廓曲线粗糙。工作轮廓曲线不是等进平面螺旋线、影响工件表面质量及刀具使用寿命。最近我厂采用以分段圆弧相衔接的曲线来代替凸轮等进平面螺旋线的解析计算方法设计加工凸轮。经实践证明这种方法有如下优点。 1.计算方法精确可靠,凸轮升高半径最大误差值可控制到几忽米(Cmm),所以与理论等进螺旋线误差小。能明显提高工件表面质量,且延长刀具使用     

模具型腔数控粗铣工艺分析研究

进行了模具型腔数控铣削加工工艺分析研究。介绍了数控铣削刀具与切削用量。对模具型腔加工特征进行详细分析,基于UGNX软件确定了对应于各种特征的加工方法和刀具。提出了模具型腔粗铣加工刀具简易组合方法,进行了走刀方式分析比较。     

NX软件在异形型面零件数控加工中的应用

针对某复杂异形型面零件,借助数字化设计与计算机辅助制造功能,应用NX软件进行数控加工工艺设计。研究了应用NX软件进行异形型面零件数控加工自动编程的一般方法,进行了型腔铣粗加工、固定轴轮廓铣半精加工、区域轮廓铣精加工、变轴曲面轮廓加工工艺设计,并进行了三维仿真验证,进而通过后处理生成机床可识别的数控加工程序。     

Research on tool path planning method of four-axis high-efficiency slot plunge milling for open blisk

The great mass of machining allowance for blisk is removed in the rough milling, so improving the rough machining efficiency for the blisk’s tunnel is the key of realizing high-efficiency machining of blisk. According to the structure characteristic of open blisk’s tunnel, a four-axis plunge slot rough milling with high-efficiency and low machining cost is advanced. First, the plunge slot process for blisk and the generation process of the ruled enveloping surface for the freeform surface of the blisk’s blade are put forward. Then, the generating method of the ruled enveloping surface for the blade’s freeform surface and the tool path generation method of four-axis plunge slot milling for blisk are studied. The rough milling region of open blisk’s tunnel is determined by generating the ruled enveloping surface of blade’s offset surface, and the algorithm of tool path for four-axis plunge milling is given. When using a ruled surface to approach a freeform surface, the problem of getting boundary is solved, and the error from the calculation of tool path is avoided by the algorithm. At last, the experiment shows that comparing to the traditional side slot milling, the cutting force of four-axis plunge milling can be reduced by 60% and even the rough machining efficiency can be increased to more than double.     

开式整体叶盘通道侧铣粗加工技术的研究

整体叶盘从锻造毛坯到最终零件加工成型,需要切除大量的多余材料。本文提出了一种开式整体叶盘通道区域五坐标粗加工刀具轨迹规划方法。该方法通过生成整体叶盘薄壁叶片的直纹包络面,以确定叶盘通道粗加工区域的边界轮廓;基于直纹面五轴侧铣加工刀具轨迹双点偏置生成方式,利用投影法规划开式整体叶盘通道区域粗铣加工的刀心点轨迹与刀轴矢量方向。加工实践表明,开式整体叶盘的粗加工效率提高30%以上,同时,显著优化了后续半精加工和精加工工序的环境。     

数控铣削加工中的刀具长度补偿设定方式分析

对刀与刀具长度补偿值的设定是数控加工前的一个重要环节。对刀方式不同,刀长补的设置也不同。本文结合具体零件加工实例,以FANUC-0iM数控系统为媒介,详尽阐述了各种对刀方式及相应刀长补的不同设定。     

涡轮叶盘数控加工优化方法的研究与实现

为提高涡轮叶盘的加工效率和质量，提出了涡轮叶盘数控加工工艺方案，在粗加工阶段，采用插铣方法代替传统的点铣加工，分层加工，减小加工变形。采用UGNX进行涡轮叶盘建模，NERC-Max数控编程，VERICUT刀轨仿真。结果表明，采用插铣方法，切削效率高，刀具和叶片未发生干涉，加工阶段划分、刀轨设计合理。提出的涡轮叶盘数控加工工艺方案可行。     

用宏程序在数控铣床上编制球面加工程序

数控铣床上加工曲面一般采用软件产生刀具路径、生成程序后自动加工,或采用宏程序手工编程加工。自动生成的加工程序通常字节多,占用很多机床存储空间。而宏程序短小精炼,适合存储空间小的设备,具有很强的适应性,只要改变一两个数据就可以进行粗加工。     

Adaptive Gregory Patch Approximation to Z-Map Data

A method is proposed for Gregory surface approximation to 3D array data points. Surface approximation is the process of constructing a compact representation to model an object surface based on a fairly large number of measured 3D data points. Based on an adaptive subdivision technique, the proposed method begins with a rough initialisation of the surface and progressively refines it in successive steps in the regions where the data is poorly approximated. The method has been implemented using piecewise bicubic Gregory patches with G 1 continuity. An advantage of this approach is that the refinement is essentially local, reducing the computational requirements that permit the processing of a large number of data points This method, combined with the inverse offsetting method, can be used to obtain an offset surface without self-interference. The offset surface can be used to generate gouging-free CL tool paths for machining compound surfaces on milling machines.     

Three-dimensional tool radius compensation for multi-axis peripheral milling

Few function about 3D tool radius compensation is applied to generating executable motion control commands in the existing computer numerical control (CNC) systems. Once the tool radius is changed, especially in the case of tool size changing with tool wear in machining, a new NC program has to be recreated. A generic 3D tool radius compensation method for multi-axis peripheral milling in CNC systems is presented. The offset path is calculated by offsetting the tool path along the direction of the offset vector with a given distance. The offset vector is perpendicular to both the tangent vector of the tool path and the orientation vector of the tool axis relative to the workpiece. The orientation vector equations of the tool axis relative to the workpiece are obtained through homogeneous coordinate transformation matrix and forward kinematics of generalized kinematics model of multi-axis machine tools. To avoid cutting into the corner formed by the two adjacent tool paths, the coordinates of offset path at the intersection point have been calculated according to the transition type that is determined by the angle between the two tool path tangent vectors at the corner. Through the verification by the solid cutting simulation software VERICUTwith different tool radiuses on a table-tilting type five-axis machine tool, and by the real machining experiment of machining a soup spoon on a five-axis machine tool with the developed CNC system, the effectiveness of the proposed 3D tool radius compensation method is confirmed. The proposed compensation method can be suitable for all kinds of threeto five-axis machine tools as a general form.     

Tool orientation optimization and location determination for four-axis plunge milling of open blisks

Plunge milling has been widely adopted in the manufacturing industry to rough machine open blisks, and its objective is to remove stock material with high efficiency and machining stability. A current technique challenge is to calculate the tool orientation and locations (called plunger paths) in four-axis rough plunging of open blisks, so that the residual raw material left on the blades after roughing is close to the specified value. To address this challenge, a novel approach is proposed to optimize tool orientation and determine tool locations for four-axis plunge milling of open blisks. First, tool locations are determined with two principles without interfering the blades and hub. Second, tool orientation is optimized according to a new evaluation criterion. Then, considering the impact of previous tool paths, an in-process model of a blisk is used to calculate residual material. Finally, an experiment is conducted to verify this new approach. This approach can promote four-axis plunge milling in the open blisk manufacturing.     

基于虚拟加工技术的数控程序优化

针对传统数控程序中进给速度固定限制加工效率的缺点,开发了面向粗铣加工的数控程序优化系统。系统基于虚拟加工技术,能完成数控程序驱动下的切削过程仿真、切削力预测、碰撞检测等。系统利用粒子群进化算法,在满足加工条件的下,实现了数控程序中进给速度和主轴转速的优化,数控程序加工效率得到显著提高。