共查询到20条相似文献,搜索用时 44 毫秒
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利用球头铣刀高速铣削Cr12模具钢,研究了切削速度、进给量和切削深度对主轴和刀具切削振动的影响变化规律,结果表明随着切削速度的增加,工件振动增加缓慢,而主轴的振动迅速增加,远超过工件的振动成为主振动,主轴进给方向的振动要小于非进给方向的振动。在小进给时,随着进给速度增加各向切削振动而迅速下降,在大进给速度时,各向振动随进给速度增加保持平稳;各通道的切削振动都随着切削深度的增大而增长,因此在高速铣削过程中,主轴振动为主振动,是影响加工表面质量的主要因素。 相似文献
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针对高速铣削中广泛应用的螺旋刃球头铣刀建立刀具微元的铣削力模型,给出了瞬时切削厚度的计算方法,通过积分得出了一种新的整体铣削力模型。该模型考虑了动态铣削时刀杆振动对铣削力的影响,实验数据与仿真结果吻合较好,验证了该模型的正确性。 相似文献
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使用精密球头铣刀进行高速铣削加工可以加工出各种形状的曲面,因而在模具生产及单件零件生产中得到了广泛的应用。球头铣刀高速铣削加工的切屑形成过程有它的特殊性。因而适当选择加工参数来调整最小切削厚度可以获得更好的铣削过程。 相似文献
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基于动力学响应的球头刀五轴铣削表面形貌仿真 总被引:6,自引:0,他引:6
针对自由曲面球头刀五轴铣削中刀具与工件复杂的位姿关系,利用球头铣削刃的三维次摆线轨迹,提出一种在工件表面等距离间隔缓存残留高度、在刀具端等时间间隔缓存振动响应的双缓存离散机制,分别实现五轴铣削中的名义加工表面形貌建模与系统动态响应轨迹仿真。在此基础上,以切削刃经过工件表面残留区域的时间信息为纽带,利用系统瞬时动态位移响应的插值信息对已加工表面法向残留高度进行修正,建立考虑铣削系统动力学响应的已加工表面形貌预测模型。以变切深、变转速、恒定的刀具倾角与每齿进给量所进行的验证试验表明,提出的球头刀五轴铣削表面形貌建模方法可有效预测颤振工况与稳定铣削工况的加工表面形貌与纹理特征。 相似文献
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研究了高速加工中球头铣刀的铣削力特性。通过综合运用理论建模法和经验系数法,并引入高速切削时引起切屑动量改变所需的作用力,建立了高速切削条件下球头铣刀的铣削力模型。实验验证结果表明,理论计算值与实验测量值吻合良好。 相似文献
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E. Ozturk 《Machining Science and Technology》2013,17(3):287-311
5-axis milling operations are common in several industries such as aerospace, automotive and die/mold for machining of sculptured surfaces. In these operations, productivity, dimensional tolerance integrity and surface quality are of utmost importance. Part and tool deflections under high cutting forces may result in unacceptable part quality whereas using conservative cutting parameters results in decreased material removal rate. Process models can be used to determine the proper or optimal milling parameters for required quality with higher productivity. The majority of the existing milling models are for 3-axis operations, even the ones for ball-end mills. In this article, a complete geometry and force model are presented for 5-axis milling operations using ball-end mills. The effect of lead and tilt angles on the process geometry, cutter and workpiece engagement limits, scallop height, and milling forces are analyzed in detail. In addition, tool deflections and form errors are also formulated for 5-axis ball-end milling. The use of the model for selection of the process parameters such as lead and tilt angles that result in minimum cutting forces are also demonstrated. The model predictions for cutting forces and tool deflections are compared and verified by experimental results. 相似文献
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MODELING OF 5-AXIS MILLING PROCESSES 总被引:2,自引:0,他引:2
5-axis milling operations are common in several industries such as aerospace, automotive and die/mold for machining of sculptured surfaces. In these operations, productivity, dimensional tolerance integrity and surface quality are of utmost importance. Part and tool deflections under high cutting forces may result in unacceptable part quality whereas using conservative cutting parameters results in decreased material removal rate. Process models can be used to determine the proper or optimal milling parameters for required quality with higher productivity. The majority of the existing milling models are for 3-axis operations, even the ones for ball-end mills. In this article, a complete geometry and force model are presented for 5-axis milling operations using ball-end mills. The effect of lead and tilt angles on the process geometry, cutter and workpiece engagement limits, scallop height, and milling forces are analyzed in detail. In addition, tool deflections and form errors are also formulated for 5-axis ball-end milling. The use of the model for selection of the process parameters such as lead and tilt angles that result in minimum cutting forces are also demonstrated. The model predictions for cutting forces and tool deflections are compared and verified by experimental results. 相似文献
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Binglin Li Xuelin Wang Chenggang Li Xingxing Li 《Machining Science and Technology》2013,17(4):453-484
A new analytical cutting force model is presented for oblique cutting. Orthogonal cutting theory based on unequal division shear zone is extended to oblique cutting using equivalent plane approach. The equivalent plane angle is defined to determine the orientation of the equivalent plane. The governing equations of chip flow through the primary shear zone are established by introducing a piecewise power law distribution assumption of shear strain rate. The flow stress is calculated from Johnson-cook material constitutive equation. The predictions were compared with test data from the available literature and showed good correlation. The proposed model of oblique cutting was applied to predict the cutting forces in end milling. The helical flutes are decomposed into a set of differential oblique cutting edges. To every engaged tooth element, the differential cutting forces are obtained from oblique cutting process. Experiments on machining AISI 1045 steel under different cutting conditions were conducted to validate the proposed model. It shows that the predicted cutting forces agree with the measurements both in trends and values. 相似文献
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The machining productivity and part quality are typically limited by the regenerative chatter induced by the dynamic interactions of spindle-holder-tool combination system. The conventional chatter stability model predicts the permissible stable axial depth of cut versus spindle speed by plotting the stability lobe diagram which represents two independent regions as absolutely stable zone and instable zone divided by the critical lobe curve. In fact, it is more reasonable to be a transition stage between the stable and instable zone. This paper introduced the grade of stability (GOS) to improve the conventional chatter stability model and study the transition zone in the stability lobe diagram. The variation of transition zone width with the stability sensibilities for different order lobe curve in milling system was analyzed. Sigmoid function was used as the membership function to develop the fuzzy stability lobe model. Then, the fuzzy stability lobe diagram with an adjustable slope coefficient was implemented to improve the mould steel milling process. The improved fuzzy stability model enhances the reliability of stability lobe diagram and guarantees the chatter-free milling process. 相似文献
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During the machining of thin-walled components, the dynamic behavior of the workpiece has a significant influence on the machining process and on the quality of the machined surfaces. In this article, a hybrid simulation concept for modeling regenerative workpiece vibrations is presented, which couples a geometric workpiece model with sets of decoupled harmonic oscillators to take the workpiece dynamics into account. 相似文献
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Significant research effort has been carried out in the detection of chatter, which is one of the main barriers against titanium milling. State-of-the-art techniques are unable to satisfy requirements of industry in terms of in-process chatter detection. The present study reports the use of sensor-signal driven reconstructed phase space attractors combined with image correlation as a solution of chatter prediction during milling of titanium in industry. The method uses Poincaré sections of reconstructed phase space attractor as patterns to identify the onset of chatter in the apparently random behavior of vibrations in the milling process. Image correlation of Poincaré sections indicates the onset of chatter in the milling process. 相似文献