摆头转台加工中心五轴联动加工的后置处理与仿真验证

在对东芝BTU-14五轴加工中心结构特性、东芝TOSS999控制系统特性以及五轴联动加工编程特点进行分析的基础上,提出其五轴联动加工的后置处理算法。在该算法基础上,利用VisualC++6.0开发出单独的后置处理程序,将加工刀轨的刀位文件处理生成东芝格式的G代码文件。为了验证后置处理程序的正确性,利用数控仿真软件Vericut 7.0建立机床的仿真模型,对后置处理程序生成的G代码文件进行仿真。最后实际加工了一个测试样件,证明了后置处理程序的正确性。     

基于加工中心的弧齿锥齿轮数控工艺研究

对利用四轴联动加工中心加工弧齿锥齿轮的方法进行研究和探讨,CAM过程在UG环境下进行,直接利用了UG提供的刀轨生成功能。采用特殊手段进行后置处理,最后生成相应加工中心下加工弧齿锥齿轮的数控代码。     

经济型五轴数控机床后置处理系统研究与应用

在双转台五轴数控机床结构的基础上,通过分析机床结构坐标系和CAM加工坐标系的关系,建立其机床加工刀头运动轨迹的数学模型,推导出该类型机床的后置处理转角计算公式和坐标转换计算公式。根据推导结果,在UG/PostBuilder通用后置处理器的基础上,针对不同类型五轴联动数控机床选配特定数控系统,设定机床参数、程序和刀轨参数、NC代码格式设置,编制了双转台式五轴数控机床的专用后置处理程序,经实际加工验证可以满足经济型五轴联动后置处理的要求。     

点云直接生成刀具路径及其后置处理

通过最小化每个刀位网格单元的加工误差以确定每个刀位网格的节点位置,加权平均相关联刀位网格节点来对齐相邻刀位网格单元的边缘,生成高效合理的数控加工刀具路径.对所获得的具路径信息进行后置处理,根据机床的结构不同,采用了相应的坐标转换,生成用于三轴加工和五轴加工的G代码.利用Vericut软件,对数据点云直接加工的刀具路径进行了动态仿真,最后应用实例验证了后置处理生成G代码的有效性.     

五轴联动数控机床的后置处理方法

后置处理是数控编程的重要环节 ,它的作用是将 CAM系统生成的刀轨文件转化为机床的加工代码。五轴联动的后置处理涉及到刀位文件的转角计算和坐标变换计算 ,坐标转换关系比较复杂 ,本文研究了立卧两种状态的五轴联动数控机床的后置处理 ,在分析了机床坐标系和工件坐标系关系的基础上 ,推导了坐标变换公式 ,并开发出了相应的后置处理软件 ,其结果满足五坐标联动后置处理的要求     

基于CATIA的五轴水切割后置处理开发

针对CATIA数控加工的刀位文件,通过分析通用后置处理程序过程,开发五轴联动水切割机床的后置处理程序,解决五轴水切割数控加工的自动编程问题。实际切割结果证明,开发的后置处理程序能够正确将CATIA软件生成的APT刀位数据转换成五坐标水切割数控加工程序。     

数控抛光机床后置处理方法及图形化编程软件

后置处理是为了将刀轨文件转换为机床各轴运动参数。图形化编程是一种针对复杂零件的重要的数控编程方法。以六轴五联动数控抛光机床为例,参照工业机器人运动学,通过建立一系列坐标系并进行运动学求解,进而推导出该机床的后置处理方法。图形化编程软件是在UG基础上二次开发得到,并将后置处理方法写入软件中。在VERICUT中搭建虚拟机床进行仿真加工,仿真结果证实了该后置处理方法的正确性、图形化编程软件生成NC代码的有效性。     

基于MasterCAM的变螺距螺杆三维建模及数控加工

本文采用CAD/CAM软件对变螺距螺杆零件进行三维建模、利用MasterCAM软件的仿真模块对零件的加工过程进行仿真并经过后置处理生成数控加工代码。利用该数控程序,在四轴联动数控机床上进行实体加工并获得成功。     

双转台五轴立式机床专用后置处理算法

通过分析WABECOH双转台五轴立式数控机床各轴的运动关系,建立各轴运动关系的数学模型,并开展机床运动学求解,给出了该五轴机床后置处理的转动角度和坐标变换计算公式。根据转动角度和坐标变换的计算公式,利用C++语言开发了WABECOH五轴数控机床专用后置处理程序,基于所提后置处理方法进行了叶轮类复杂零件的加工仿真与实验验证。结果表明,所开发的专用后置处理软件生成的数控代码可以满足该机床五轴联动的要求,较好地解决了该类机床的后置处理问题。     

腔体零件的CAD/CAM一体化研究及应用

针对某一典型复杂腔体零件,从本单位实际加工情况出发,进行CAD/CAM一体化设计研究,说明了CAD/CAM一体化设计应用步骤,重点叙述了建立三维实体模型,进行工艺分析、计算,确定加工路线及加工参数,进行CAM设计,生成刀轨及刀轨文件,再经后置处理生成零件的NC加工代码,并进行刀轨校验,最后将NC程序输入加工中心设备进行仿真加工及试加工,得到合格产品。     

五轴数控空间刀具半径补偿的实现

深入分析了空间刀具半径补偿矢量的计算方法,对实现该空间刀补矢量到五轴联动数控系统中做了算法的准备和验证,并以UG NX6.0生成的刀位文件(CLSF)为坐标数据来源和五轴联动A/C双转台机床为例,开发了一个专用后置处理软件,并通过在Vericut7.0上模拟和五轴联动机床上实际加工叶片,加工结果说明了该算法的正确性和软件的实用性。     

A real-time surface interpolator methodology for precision CNC machining of swept surfaces

A real-time surface interpolator is developed to machine a family of swept surfaces directly from their high-level procedural definitions. All the computations required for machining are performed in real time based on the exact surface geometry, including tool path planning, tool path interpolation, tool offsetting, and tool path step-over to achieve a prescribed scallop height. A G-code command (G05) is introduced to concisely communicate the precise surface geometry and all necessary process parameters to the controller. The swept surface interpolator offers profound accuracy and efficiency advantages over the traditional approach of generating voluminous piecewise–linear/circular tool path approximations as a preprocessing step. For example, in one instance, a 36,000-line piecewise-linear (G01) approximate part program file is replaced by a 3-line exact swept surface (G05) part program file. The methodology is verified by machining a variety of swept surface forms in aluminum and wax, using a 3-axis milling machine with the surface interpolator incorporated into an open-architecture CNC controller.     

Postprocessor development for ultrasonic cutting of honeycomb core curved surface with a straight blade

When ultrasonically cutting honeycomb core curved parts, the tool face of the straight blade must be along the curved surface’s tangent direction at all times to ensure high-quality machining of the curved surface. However, given that the straight blade is a nonstandard tool, the existing computer-aided manufacturing technology cannot directly realize the above action requirement. To solve this problem, this paper proposed an algorithm for extracting a straight blade real-time tool face vector from a 5-axis milling automatically programmed tool location file, which can realize the tool location point and tool axis vector conversion from the flat end mill to the straight blade. At the same time, for the multi-solution problem of the rotation axis, the dependent axis rotation minimization algorithm was introduced, and the spindle rotation algorithm was proposed for the tool edge orientation problem when the straight blade is used to machine the curved part. Finally, on the basis of the MATLAB platform, the dependent axis rotation minimization algorithm and spindle rotation algorithm were integrated and compiled, and the straight blade ultrasonic cutting honeycomb core postprocessor was then developed. The model of the machine tool and the definition of the straight blade were conducted in the VERICUT simulation software, and the simulation machining of the equivalent entity of the honeycomb core can then be realized. The correctness of the numerical control program generated by the postprocessor was verified by machining and accuracy testing of the two designed features. Observation and analysis of the simulation and experiment indicate that the tool pose is the same under each working condition, and the workpieces obtained by machining also meet the corresponding accuracy requirements. Therefore, the postprocessor developed in this paper can be well adapted to the honeycomb core ultrasonic cutting machine tool and realize high-quality and high-efficient machining of honeycomb core composites.     

基于OpenGL的五轴数控铣削仿真

在UG中进行多轴加工后处理时,由于选项设置和机床数据文件配置不当,会导致生成的G代码程序存在错误.为了及时发现程序中的错误,利用OpenGL三维图形接口,在Visual C++开发环境下实现了五轴G代码程序的离线和在线仿真功能,集成到自行开发的等离子熔积铣削复合机床上位机软件中;并利用仿真功能进行了铝合金整体叶轮的铣削加工试验.     

Postprocessor development of a five-axis machine tool with nutating head and table configuration

The postprocessor is an important interface that transforms cutter location data into machine control data, and in a five-axis machine tool is highly complex because the simultaneous linear and rotary motions occur. Since most works of the five-axis postprocessor method have dealt only with the orthogonal machine tool’s configuration, this study presents a postprocessor scheme for two types of five-axis machine tools, each with a nutating head and a table whose rotational axes are in an inclined plane. The benefit of such a configuration is that it allows switching from vertical to horizontal machining by a single machine. The general analytical equations of NC data are obtained from the forward and inverse kinematics and the homogeneous coordinate transformation matrix. The linearization algorithm for the postprocessor is developed to ensure the machining accuracy. The presented algorithm is implemented using a window-based five-axis postprocessor with nutating axes, and programmed in Borland C++ Builder and OpenGL. A simulation is performed using solid cutting software and a trial-cut experiment was conducted on a five-axis machine tool with a nutating table to elucidate the accuracy of the proposed scheme.     

基于VC的数控机床转换程序设计

分析了五轴龙门铣床FPF—N／C和Fpm-60的机床结构和运动特点及数控系统特点,计算出后置处理的相关算法,开发了基于VC的数控机床转换程序,经过加工证明了开发的转换程序的正确性。     

Tool path optimization in postprocessor of five-axis machine tools

Generally, tool path is generated in a computer-aided manufacturing software considering only the geometry of machining parts. It is converted into numerical control (NC) codes in the postprocessor based on the particular machine kinematics. For some special types of five-axis machine tools, e.g., non-orthogonal five-axis machine tools, the generated NC codes may produce unqualified parts because of the existence of the non-linear error. Conventional commercialized postprocessors usually do not have the function of non-linear error checking. Observing that the tool path is a non-smooth trajectory full of corners and a series of connected line segments, cubic spline interpolation is applied to smooth the tool path at regular points in this study. The cutter tip center points are computed by the cubic spine interpolation, while the cutter posture vectors are obtained via linear interpolation. At the splines (for regular points) and the line segments (feature points), more points are chosen to be converted into NC codes to reduce the non-linear error, which is called data densification. Using the cubic spline to smooth the tool path and the data densification to reduce the non-linear error, a novel tool path optimization algorithm in postprocessor is proposed. Experiments were carried out on an inclined rotary spindle axis non-orthogonal five-axis machine tool. It shows that the proposed tool path optimization provides improved accuracy and surface quality.     

基于NX软件的回转曲面单线汉字四轴加工

介绍了在NX软件中产生汉字的两种方法,分析了回转曲面上单线汉字的刀轨问题,并通过定制后处理程序输出四轴加工数控程序。基于NX软件实现回转曲面单线汉字四轴加工,可以在回转零件表面上进行刻字、刻线或刻标记等四轴加工操作,进而提高加工自动化水平与效率。     

基于UG的后置处理和加工仿真技术研究

针对典型结构件在DMU50 e机床的数控铣削加工,研究将UG软件的刀位文件生成机床用程序的问题,首先提出了后置处理中重要的机床运动变换和字符转换方法,而后利用C语言编制了数控系统SIEMENS 840D的后置处理程序。最后通过实例仿真加工验证了方法的可行性。