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钛合金型腔圆角加工容易发生切削负载增大和颤振等现象,导致圆角表面质量较差,难以实现钛合金高效加工。通过钛合金型腔圆角铣削试验,基于铣削力和圆角表面质量检测,分析内圆角铣削特征和原理,并优化铣削参数。试验表明:采用小切削宽度的高速加工,可实现钛合金内圆角的高效加工;在Vc=90m/min,ft=0.06mm/t,ap=20mm,ae=1mm切削参数组合下,切削力相对较小,加工效率高,切削表面质量高。 相似文献
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立铣加工动态切削力预测新方法及应用 总被引:1,自引:1,他引:0
通过切削力物理建模、仿真和应用研究来准确地预测切削力,是进行工艺优化的必要前提.动态切削力的预测对于研究切削机理和加工质量的控制都很重要.提出了一种新的螺旋立铣刀加工中动态切削力建模方法,通过微元法建立的切削力数学模型和斜角等厚度切削有限元模型两者结合,对高速铣削淬硬模具钢SKD11的动态切削力进行预测,并且对误差来源进行了分析.本建模方法通过建立单刃切削力数学模型,然后结合有限元分析得到单刃切削力曲线,经离散数据叠加后得到加工过程的动态铣削力曲线.此方法可避免传统建模中需要大量试验求取多个系数且预测精度差的特点.最后通过分析影响结果的主要因素及参数调节方法,保证了预测精度. 相似文献
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小直径铣刀高速铣削淬硬模具钢不同走刀方式下切削力和加工效率的研究 总被引:1,自引:0,他引:1
高速加工是制造技术的一次革命性变革,是当今机械加工技术不可抗拒的发展潮流.小直径铣刀高速加工硬质模具钢时不同的切削条件及切削方式又是影响切削力的重要因素之一.本文主要研究刀具以不同走刀方式,在圆弧拐角处改变不同的进给速度铣削淬硬钢带岛屿的型腔时对切削力、及加工时间的影响情况,从而得出在同样的切削条件下摆线式走刀时刀具所受到的切削力较小,但是其加工效率也较低,相比之下圆弧走刀时刀具所受到的切削力较大而切削效率却较高的结论.故在高速加工时从保护刀具的角度出发易选用摆线走刀方式. 相似文献
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切削力模型可以计算切削过程的切削力,是预测加工状态、优化加工参数的依据。传统的切削力预测模型都是针对工件坐标系建立的,然而在研究薄壁件多轴加工让刀变形、振动以及刀具磨损等问题时,基于刀具坐标系的切削力表示方式更为直观。为了预测刀具坐标系的切削力,在传统机械切削力模型的基础上,提出了刀具坐标系铣削力预测模型,并提出了基于刀具坐标系测量结果的切削力系数标定方法,最后通过实验验证了所提出的切削力预测模型和切削力系数标定方法,实验结果表明所提出的切削力模型能够准确地预测实际加工中的切削力。 相似文献
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通过切削振动物理模型,分析了刀具产生切削振动的原因以及降低切削力、抑制刀具振动的方法。刀具系统静态和动态刚度对大悬径比深孔和型腔加工切削振动影响较大,重点介绍了提高刀具系统刚度的削振措施。 相似文献
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当前市场上的数控系统均无椭圆台型腔加工固定循环功能,一般也没有椭圆插补功能.为了扩展数控系统的功能,通过建立用球刀加工椭圆台型腔的数学模型,计算出了刀心变高切削等高线时的刀心坐标,并编写了宏程序,然后设置成椭圆台型腔加工固定循环G代码,给出了椭圆台型腔加工的误差预测方法.可用于椭圆台型腔、圆变椭圆型腔、圆台形型腔、椭圆柱型腔及圆柱形型腔的数控编程,并通过实例验证了数学模型及宏程序的正确性. 相似文献
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针对零件轮廓曲率半径和精加工余量对切削力的影响,通过正交切削实验,获得轮廓曲率半径、精加工余量与峰值切削力之间的相互影响关系,提出了一种适用于变曲率轮廓铣削的恒切削力2D轮廓铣削刀具路径生成算法。通过生成一条新的偏置路径,即修正的半精加工刀具路径,调节精加工路径各处余量。将此算法应用于包含自由曲线轮廓的不规则型腔加工,结果表明,该算法可以使精加工中的峰值切削力维持在一个恒定的状态,从而改善了加工质量。 相似文献
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在拉深凹模的加工中,型腔部分的加工通过一般数控程序很容易解决,但凹模圆角部分却很难加工。通常我们采用三种方式加工凹模圆角,一是由钳工手工修锉,这种方法工作量大,很难达到要求,且一致性比较差;二是用成形R铣刀直接加工,这种方法对刀具刃磨比较严格,刀具两切削刃很难磨对称, 相似文献
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Wen-Hou Chu Pi-Cheng Tung 《The International Journal of Advanced Manufacturing Technology》2005,25(3-4):281-287
In end milling of pockets, variable radial depth of cut is generally encountered as the end mill enters and exits the corner, which has a significant influence on the cutting forces and further affects the contour accuracy of the milled pockets. This paper proposes an approach for predicting the cutting forces in end milling of pockets. A mathematical model is presented to describe the geometric relationship between an end mill and the corner profile. The milling process of corners is discretized into a series of steady-state cutting processes, each with different radial depth of cut determined by the instantaneous position of the end mill relative to the workpiece. For the cutting force prediction, an analytical model of cutting forces for the steady-state machining conditions is introduced for each segmented process with given radial depth of cut. The predicted cutting forces can be calculated in terms of tool/workpiece geometry, cutting parameters and workpiece material properties, as well as the relative position of the tool to workpiece. Experiments of pocket milling are conducted for the verification of the proposed method. 相似文献
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K. W. Chan H. S. Choy 《The International Journal of Advanced Manufacturing Technology》2002,20(10):741-748
The cutter–workpiece contact of an end mill fluctuates when cutting along a curvilinear tool path. It increases sharply when
reaching a concave corner. Since conventional contour-parallel tool-path cutting does not take this condition into account,
it will cause a momentarily rise of cutting resistance in concave corner regions, producing undesirable effects such as machine
chatter, gouging and even cutter breakage.
This paper proposes to use machining tactics in which a corner-looping tool path is employed to remove progressively the concentrated
material at corner regions, thereby restricting the cutting resistance to an acceptable level. Different corner types are
categorised and the procedures of generating the proposed machining tactics are described. Experimental results demonstrate
that using the proposed machining tactics can significantly control and reduce the cutting resistance fluctuation encountered
in concave corner regions.
ID="A1"Correspondance and offprint requests to: Dr H. S. Choy, Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong. E-mail: hangshan@hkem.com 相似文献
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针对微细切削刀具的特点与应用需求,设计一种斜圆柱结构的新型微细球端铣刀,将铣刀球端刀刃复杂的空间曲线转化为易加工的平面曲线。根据所设计铣刀的几何结构特征,从制造工艺方面进行刀具结构的调整,分析刀具的刃磨成形原理,并在微细刀具数控刃磨机上完成该刀具的制作。通过与传统螺旋槽球端铣刀和椭圆柱刃型球端铣刀的切削性能对比试验,研究所设计刀具的切削性能。试验结果表明,所设计的微细球端立铣刀在显著降低刀具制备难度的同时,具有较高的切削刃强度,能够满足硬脆性材料的微细切削要求。 相似文献
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V. P. Cherkashin 《Russian Engineering Research》2008,28(11):1088-1090
The characteristics of an end mill with equal life of the lateral and end cutters are studied experimentally. Half the cutting units of the mill differ from the standard units in that they do not include lateral cutters. A distinct cutting system has been developed for an end mill with equal life of the end and lateral cutters. This system, initially intended for hobbing heads, may be extended also to other cutting tools—in the present case, an end mill well-suited to the machining of planes, slots, and projections. 相似文献
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Kazumasa Kawasaki Takashi Nishiguchi Toshiro Miyajima Satoru Higuchi Katsuya Fukazawa 《Machining Science and Technology》2013,17(1):93-109
The precision cutting of a molding die is realized using a square end mill on a 5-axis control machine. In this study, first the tool setting errors are analyzed and the compensation method of the errors is proposed. The effectiveness of compensation in precision cutting is confirmed. Next, the form accuracy of the spiral tool pass is compared with contour one in precision cutting of a spherical surface. Finally, the molding die with spherical surface is manufactured using a square end mill made out of single-crystal diamond based on the results of the compensation of the errors and the comparison of the two tool passes, and the form accuracy and surface roughness of the molding die are measured. 相似文献
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针对淬硬钢铣削时易产生高频振动以及刀具剧烈磨损导致耐用度低等问题,基于成形槽技术开发出芯部直径与铣刀直径比值达0.7的高刚性立铣刀,推导了螺旋槽径向截面形状的数学模型。进行了切削仿真和静力学仿真,仿真结果表明:较对比刀具,高刚性立铣刀平均切削力更大,切削温度和容排屑性能相差无几,刀具变形量更小。最后开展了切削实验验证研究,研究结果表明:较对比刀具,高刚性立铣刀加工零件表面粗糙度值由0.30 μm下降到0.16 μm,让刀量由0.18 mm减小到0.08 mm,刀具耐用度则由35 min提高到58 min,体现了高刚性立铣刀的性能优势。 相似文献
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Effect of tool stiffness upon tool wear in high spindle speed milling using small ball end mill 总被引:1,自引:0,他引:1
Longer tool life can be tentatively achieved at a higher feed rate using a small ball end mill in high spindle speed milling (over several tens of thousands of revolutions per minute), although the mechanism by which tool life is improved has not yet been clarified. In the present paper, the mechanism of tool wear is investigated with respect to the deviation in cutting force and the deflection of a ball end mill with two cutting edges. The vector loci of the cutting forces are shown to correlate strongly with wear on both cutting edges of ball end mills having various tool stiffnesses related to the tool length. The results clarified that tool life can be prolonged by reducing tool stiffness, because the cutting forces are balanced, resulting in even tool wear on both cutting edges as tool stiffness is lowered to almost the breakage limit of the end mill. A ball end mill with an optimal tool length showed significant improvement in tool life in the milling of forging die models. 相似文献
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Anhai Li Jun Zhao Zhiqiang Pei Ningbo Zhu 《The International Journal of Advanced Manufacturing Technology》2014,71(9-12):1889-1900
Designing a high-performance solid carbide end mill is difficult due to the complex relationship between end mill geometry and numerous or conflicting design goals. Earlier approaches of computer-aided solid end mill design are limited to only a few design aspects. This article presents a three-dimensional finite element method of milling process for solid carbide end mill design and optimization. The software was secondarily developed based on UG platform, integrating the parametric design with the development of the two-dimension drawing of solid carbide end mill. The three-dimension finite element simulation for milling Ti-6Al-4V alloy was performed and the geometrical parameters were optimized based on the objective of low cutting force and cutting temperature. As a result, a simulation-based design and optimization of geometrical parameters of tool structure and cutting edge is possible. The optimized results, for the geometrical parameters of tool structure and cutting edge when milling titanium alloy using a 20-mm diameter solid carbide end mill, is a 12-mm diameter of inner circle, four flutes, a 45 ° helix angle, and a 9 ° rake angle of the side cutting edge. 相似文献