共查询到20条相似文献,搜索用时 890 毫秒
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Hua Qiu Akio Kubo Zi-Ye Li Yong Yue 《The International Journal of Advanced Manufacturing Technology》2008,36(1-2):69-82
In NC machining of noncircular contours with a rotation table, the cutter is fed along a straight line intersecting perpendicularly
the rotation axis of the work piece. In this situation, the cutter path usually consists of a series of Archimedes’ spiral
segments. This paper proposes an optimal interpolation approach of Archimedes’ spiral segments to generate the cutter path
for machining noncircular contours. The number of segments for the cutter path resulted from the approach is the fewest under
the condition that the interpolation accuracy completely satisfies the specified limit value. It has been also evidenced that
the profile error of the machined contours corresponding to the cutter path is perfectly controlled within the specified interpolation
accuracy limit. The effectiveness of the proposed approach has been sufficiently confirmed by applying it to machining a disc
cam and an algebraic spiral type of scroll wrap. 相似文献
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J. N. Lee 《Journal of Mechanical Science and Technology》2007,21(10):1644-1650
The geometry of helical milling cutter with specific cross-section profile is normally generated with form cutter by the toolpath
generating method. The general purpose CAD/CAM software can generate the cutter location file of this class of product only
by the sculpturing method. To obtain the flexibility of machining process, this paper presents an interference-free toolpath
generating method for semi-finish and finish machining of the helical milling cutter. The method for design and machining
of the helical milling cutter is established based on the differential geometry and the enveloping theory. In the finish machining
of helical milling cutter, the form grinding wheel profile is firstly derived. To reduce the cost and lead time of the generating
method with the form-mill cutter for semi-finish machining, a toolpath generating method which combines the advantages of
the generating method and sculpturing method was presented. The cutter location uses ball-nose conical end mill is derived
according to the geometric characteristics of the enveloping element. The cutting simulations with solid model were performed
to verify the proposed toolpath generation method. 相似文献
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A New Tool-Path Generation Method Using a Cylindrical End Mill for 5-Axis Machining of a Spatial Cam with a Conical Meshing Element 总被引:2,自引:2,他引:0
R. S. Lee J. N. Lee 《The International Journal of Advanced Manufacturing Technology》2001,18(9):615-623
The geometry of a spatial cam is normally generated using a form-milling cutter and a special multi-axis machine and software.
The general purpose CAD/CAM software can generate the cutter location file of this class of product only by the sculpturing
method. Because of the limited choice of cutting tool when using the generating method, this paper presents a new toolpath
generating method which combines the advantages of the generating and sculpturing methods for machining a spatial cam. In
the machining process, the cutter location is derived for rough and finish machining using a cylindrical end mill. The guidelines
for choosing cutter diameter for the machining process are discussed. To avoid interference, the principal curvatures and
the principal induced normal curvatures are analysed. The mathematical errors including chordal deviation and scallop height
are used as the basis for generating appropriate tool-paths. Cutting simulation of a solid model was performed to verify the
proposed tool-path generation method. 相似文献
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整体叶轮五轴侧铣数控加工方法的研究 总被引:7,自引:0,他引:7
为提高整体叶轮的五轴编程和加工的能力,生成合理的刀位文件,在制定出合理的加工工艺的基础上,提出了一种适合于直纹面叶片五轴侧铣加工的刀轴矢量计算方法.对两个相邻叶片的直母线进行插值后,得到的刀轴矢量能完全避免刀具与叶片之间的干涉问题.同时,提出了一种小四边形参数模型来解决直线与自由曲面求交问题,并成功应用于刀心计算中.实例计算表明,所提出的方法能很好地应用于整体叶轮的五轴加工. 相似文献
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A new tool path generation method for sheet metal computer numerically controlled incremental forming was proposed based on the stereolithography model, considering the factors of sheet thickness variation, surface smoothness, and extruding direction. The new cutter contact surface modeling algorithm based on the non-equidistant offset was presented, which can be adapted to the sheet thickness variation so as to guarantee a reasonable gap between the forming tool and support. Moreover, a spiral tool path generation algorithm was introduced by considering the scallop height in both z-axis direction and circumferential rotation direction, so that a smoother surface can be obtained. In addition, the algorithm for keeping the tool direction perpendicular to the wall surface was also presented. Finally, the case study shows that the proposed method can automatically generate smooth and continuous spiral tool path with constant scallop height. The developed software system runs steadily and reliably. 相似文献
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Dongwei Ao Xingrong Chu Yang Yang Shuxia Lin Jun Gao 《The International Journal of Advanced Manufacturing Technology》2018,95(9-12):3197-3213
Because the intermediate-stage forming surface and the intermediate-stage forming tool path of the complex shape model are difficult to generate, the existing multi-stage CNC incremental forming takes the regular rotary body model or the square model as the research objects, and all adopt the three-axis CNC incremental forming mode. In this paper, a method for generating the intermediate-stage surface by using a longitude line that can reflect the personality of the surface and the five-axis CNC multi-stage incremental forming tool path was proposed. Firstly, the vertexes of the triangular facets of the STL model are used to generate the longitude lines which can reflect the characteristic of the surface, then the longitude lines are offset according to the multi-stage forming strategy and the characteristics of each surface associated with the longitude lines so that the intermediate-stage longitude lines could be generated, and then the intermediate-stage surfaces are built using the intermediate-stage longitude lines. Finally, the cutter location points of each intermediate stage are obtained by cutting the intermediate-stage surfaces, and the postures of the five-axis CNC pressing tool are determined according to the normal vector of the cutter location points. The case studies show that the proposed method can well generate the five-axis CNC multi-stage incremental forming path for the complex shape sheet metal part. The results of the numerical simulation analysis and forming experiments show that the proposed method is applicable. 相似文献
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Dr Yean-Ren Hwang Cha-Shong Liang 《The International Journal of Advanced Manufacturing Technology》1998,14(6):399-405
Current computer-aided manufacturing (CAM) systems generate cutter contact points (CC points), cutter location points (CL points) and cutter orientation angles (CO angles) based only on the sculptured surface geometry. However, under certain situations, the cutting errors of 5-axis NC machines are larger than expected using these CC, CL and CO data. It is shown in this paper that the cutting error depends on the structures of 5-axis NC machines as well as the surface geometry. A new algorithm has been developed to estimate the cutting error and calculate the maximum allowable step length for spindle-tilting type 5-axis NC machines. Simulation results show that the new algorithm provides better estimation on the cutting errors for spindle-tilting type 5-axis NC machines. 相似文献
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并联机床后置处理算法与系统 总被引:6,自引:0,他引:6
以6自由度6-TPS型并联机床为模型,阐述了生成控制数据的一般流程,指出后置处理必须解决的两个关键问题——工件坐标系定位和动平台位姿获取。针对不同位形,提出利用综合误差系数和综合误差度来评价终端运动精度,并据此将工件坐标系定位归结为一类兼顾作业空间和运动精度的有约束非线性规划问题;提出了一种利用5自由度刀位文件获得6自由度动平台位姿的方法;研究了笛卡儿空间的插补算法,并比较了两种不同方法所产生的不同刀具插补轨迹。最后介绍了基于以上算法所开发的后置处理系统的结构。 相似文献
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B样条列表曲线直线插补的自适应算法 总被引:1,自引:0,他引:1
给出了一种根据零件加工精度要求,对三次B样条列表曲线进行直线插补,自动生成变步长刀位轨迹的算法,简称自适应算法。该算法当列表曲线曲率大时,使步长变小,反之使步长变大,同时使逼近误差满足要求。该算法稳定、可靠,便于在列表曲线、列表曲面的数控加工中推广应用。 相似文献
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薄壁件不一致刀齿铣削时铣削力系数构造与预测 总被引:1,自引:0,他引:1
针对薄壁件铣削过程中刀齿半径不一致现象引起的铣削力系数计算失真问题,提出构造刀齿半径不一致时的实际铣削力系数,并采用核偏最小二乘法对不同铣削用量时的实际铣削力系数进行预测。针对两齿螺旋铣刀铣削过程推导理论铣削力系数,根据刀齿半径不一致铣削过程引入名义铣削力,推导刀齿半径误差,构造实际铣削力系数;基于核分析方法突出的非线性分析及预测能力,提出采用核偏最小二乘法在高维空间建立实际铣削力系数关于铣削用量及其组合量的预测模型,分析该方法中核主元个数、高斯核函数核参数对预测模型精度的影响并确定其取值范围。最后分析考虑刀齿半径误差与不考虑时的铣削力系数,并比较核偏最小二乘预测方法与偏最小二乘预测方法,结果表明所提铣削力系数构造过程及预测方法具有较高的计算精度和预测能力。 相似文献
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针对目前航空发动机叶片进排气边加工精度和表面质量较差的问题,提出了一种基于机床运动学约束球头刀多轴加工刀轴矢量优化方法。建立刀位优化变量与刀位数据之间的关系方程,同时建立刀位数据与机床回转轴角度之间的运动变换方程,从而推导出刀位优化变量与机床回转轴角度之间的关系方程。通过求解上述方程得到球头刀多轴加工复杂曲面的刀轴矢量计算公式。在此基础上,给出球头刀多轴加工刀轴矢量优化方法和刀轨生成方法。同时,以某航空发动机叶片为例,分析了本文算法和Sturz算法对机床回转轴角度的影响。分别利用本文算法和Sturz算法生成该叶片进气边加工的刀轨,并在五轴数控机床上进行加工试验。试验结果表明,该算法能够避免加工过程中机床回转轴的大幅波动,使机床轴运动更加平稳和光滑,从而提高曲面的加工质量和加工效率,具有一定的实际应用价值。 相似文献