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可转位浅孔钻的设计与应用 总被引:6,自引:5,他引:1
通过对力的分析,提出了可转位浅孔钻的设计原则。为保证钻头背向力的平衡,推导出了旋转角β的计算公式。对可转位浅孔钻备组成零件的设计、刀片搭接量的大小、几何参数的选择、冷却方式、切削用量、使用注意事项及加工效果等作了概述。 相似文献
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基于FEM的可转位浅孔钻钻削应力分析 总被引:1,自引:0,他引:1
以安装两片硬质合金刀片的可转位浅孔钻为例,对浅孔钻的刀片所受应力进行了研究。根据内外两个刀片的切削刃在加工中的实际状态,分别对其建立有限元模型,利用Matlab对刀片在优化后稳态加工时有效切削刃的载荷分布进行了多项式拟合,并进行了应力分析;在不同切削用量时对刀片的应力变化情况进行了数值仿真。为浅孔钻结构(主要是刀片槽形)设计、使用的刀片的几何参数的确定,以及加工中切削用量的选用等提供了理论模型和可供参考的结构参数,而且所建立的模型和所采用的研究方法为其它类型的可转位刀具切削力的计算与数值仿真提供了可供借鉴的途径。 相似文献
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对可转位浅孔钻进行受力分析,推导内刀片偏置角β计算公式。通过可转位浅孔钻切削试验,分析其切削力和被加工件尺寸随角β的变化趋势,对内刀片偏置角β进行验证。 相似文献
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可转位浅孔钻参数优化的数值解法 总被引:2,自引:0,他引:2
采用斜角切削理论和试验相结合的方法建立可转位浅孔钻钻削力数值仿真的数学模型。该模型用于研究刀片在刀体上的空间位置参数对钻削力和扭矩的影响,并在给定已知条件下求出经过优化的径向合力为最小的刀片位置参数。 相似文献
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可转位浅孔钻的主要优点是允许采用比其它钻头高得多的进给量和切削速度。但由于其刀片是非对称安装,因此切削时可使机床主轴—轴承系统要承受较大的径向载荷。本文简介了首批试验研究结果,并对装有正方形硬质合金可转位刀片的浅孔钻,指出了克服其缺点可能采取的办法。 相似文献
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《机械工程学报(英文版)》2017,(1)
Titanium alloy is a kind of typical hard-to-cut material due to its low thermal conductivity and high strength at elevated temperatures, this contributes to the fast tool wear in the milling of titanium alloys. The influence of cutting conditions on tool wear has been focused on the turning process, and their influence on tool wear in milling process as well as the influence of tool wear on cutting force coefficients has not been investigated comprehensively. To fully understand the tool wear behavior in milling process with inserts, the influence of cutting parameters on tool wear in the milling of titanium alloys Ti6Al4 V by using indexable cutters is investigated. The tool wear rate and trends under different feed per tooth, cutting speed, axial depth of cut and radial depth of cut are analyzed. The results show that the feed rate per tooth and the radial depth of cut have a large influence on tool wear in milling Ti6Al4 V with coated insert. To reduce tool wear, cutting parameters for coated inserts under experimental cutting conditions are set as: feed rate per tooth less than 0.07 mm, radial depth of cut less than 1.0 mm, and cutting speed sets between 60 and 150 m/min. Investigation on the relationship between tool wear and cutting force coefficients shows that tangential edge constant increases with tool wear and cutter edge chipping can lead to a great variety of tangential cutting force coefficient. The proposed research provides the basic data for evaluating the machinability of milling Ti6Al4 V alloy with coated inserts, and the recommend cutting parameters can be immediately applied in practical production. 相似文献
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Titanium alloy is a kind of typical hard-to-cut material due to its low thermal conductivity and high strength at elevated temperatures, this contributes to the fast tool wear in the milling of titanium alloys. The influence of cutting conditions on tool wear has been focused on the turning process, and their influence on tool wear in milling process as well as the influence of tool wear on cutting force coefficients has not been investigated comprehensively. To fully understand the tool wear behavior in milling process with inserts, the influence of cutting parameters on tool wear in the milling of titanium alloys Ti6Al4V by using indexable cutters is investigated. The tool wear rate and trends under different feed per tooth, cutting speed, axial depth of cut and radial depth of cut are analyzed. The results show that the feed rate per tooth and the radial depth of cut have a large influence on tool wear in milling Ti6Al4V with coated insert. To reduce tool wear, cutting parameters for coated inserts under experimental cutting conditions are set as: feed rate per tooth less than 0.07 mm, radial depth of cut less than 1.0 mm, and cutting speed sets between 60 and 150 m/min. Investigation on the relationship between tool wear and cutting force coefficients shows that tangential edge constant increases with tool wear and cutter edge chipping can lead to a great variety of tangential cutting force coefficient. The proposed research provides the basic data for evaluating the machinability of milling Ti6Al4V alloy with coated inserts, and the recommend cutting parameters can be immediately applied in practical production. 相似文献
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This study is focused on some physical and technological aspects of a precise turning with Self-Propelled Rotary Tool (SPRT). As part of experiment, the cutting forces, on-line insert run-out and machined surface topography were investigated. Turning tests were carried in the range of variable feeds, depths of cut and cutting speeds for a hardened 41Cr4 steel with the use of a coated carbide round indexable inserts. The effect of cutting conditions on the tool rotation and the dynamics of cutting force signal were evaluated. In particular, changes of cutting forces vs. cutting lengths for different cutting parameters were analyzed in terms of the cutting insert rotation, and Power Spectral Density (PSD) analysis. Moreover, the original method based on cutting force oscillations was employed to estimate the on-line insert run-out. Ultimately, the analysis of a machined surface topography was conducted, considering the interactions between the process inputs and outputs. It was shown that application of high cutting speeds and feeds during SPRT turning can lead to the improvements in surface finish, as well as the stabilization of cutting force values. 相似文献
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Durwesh Jhodkar M. Amarnath H. Chelladurai J. Ramkumar 《Journal of Mechanical Science and Technology》2018,32(6):2551-2558
This study attributed to post treatment of tungsten carbide (WC) inserts using microwave irradiation. Tungsten carbide inserts were subjected to microwave radiation (2.45 GHz) to enhance its performance in terms of reduction in tool wear rate, cutting force surface roughness and improvement in tool life. Performance of tungsten carbide insert is very much affected by machine operating parameters i.e. speed, feed and depth of cut. An attempt has been made to investigate the effects of machining parameters on microwave treated tool inserts. This paper describes the comparative study of machining performance of untreated and microwave treated WC tool inserts used for turning of AISI 1040 steel. Machining performance has been evaluated in terms of flank wear, cutting force, surface roughness, tool wear mechanisms. Critical examinations of tool wear mechanisms and improvements in metallurgical properties such as microstructural change, phase activation of WC grains were identified using scanning electron microscope (SEM). Results obtained from the turning using the microwave treated tool inserts showed a significant reduction tool wear thereby enhancing the surface quality of workpiece. 相似文献
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J.P. Choi S.J. Lee 《The International Journal of Advanced Manufacturing Technology》2001,17(7):489-497
As machining technology develops toward the unmanned and automated system, the need for chip control is considered increasingly
important, especially in continuous machining such as in the turning operation. In this study, a systematic chip breaking
prediction method is proposed using a 3D cutting model with the equivalent parameter concept. To verify the model, four inserts
with different chip breaker parameters were tested and their chip breaking areas were compared with those obtained from the
model. Finally, a new type insert (MF1) for medium-finish operations with variable parameters was designed by modifying the
commercial one. The chip breaking region predicted by using the modified 3D cutting model for the above insert agrees with
the one obtained experimentally. The newly designed insert showed better chip breaking ability than the base model, and other
performance tests such as surface roughness, cutting force and tool wear also showed good results. 相似文献
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Titanium alloys are difficult-to-machine materials because of their poor machinability characteristics. Machining and machining performance evaluation for such materials is still a challenge. Individual machining performance indices like cutting forces, cutting energy and tool wear lead to ambiguous understanding. In this work, a Cumulative Performance Index (CPI) is defined which amalgamates non-dimensional forms of specific cutting energy, back force and average principal flank wear in turning. The CPI focuses upon simultaneous minimization of specific cutting energy, dimensional deviation and average principal flank wear. The defined index is then used to evaluate performance of five commercially available physical vapor deposited (PVD) TiAlN coated tungsten carbide/cobalt inserts vis-à-vis uncoated tungsten carbide/cobalt insert in turning of Ti-6Al-4V. Cutting forces were monitored during turning and tool wear was measured after turning experiments. The results showed that the performance of coated inserts was either comparable or poor than uncoated insert; and in no case, coated inserts performed better than uncoated insert. Although commercial recommendations are in place to use PVD coated inserts for enhanced machinability of titanium alloys, the use of coated inserts is not justified keeping in view the energy spent in coating and insignificant improvement in performance. 相似文献
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The present work deals with some machinability studies on flank wear, surface roughness, chip morphology and cutting forces in finish hard turning of AISI 4340 steel using uncoated and multilayer TiN and ZrCN coated carbide inserts at higher cutting speed range. The process has also been justified economically for its effective application in hard turning. Experimental results revealed that multilayer TiN/TiCN/Al2O3/TiN coated insert performed better than uncoated and TiN/TiCN/Al2O3/ZrCN coated carbide insert being steady growth of flank wear and surface roughness. The tool life for TiN and ZrCN coated carbide inserts was found to be approximately 19 min and 8 min at the extreme cutting conditions tested. Uncoated carbide insert used to cut hardened steel fractured prematurely. Abrasion, chipping and catastrophic failure are the principal wear mechanisms observed during machining. The turning forces (cutting force, thrust force and feed force) are observed to be lower using multilayer coated carbide insert in hard turning compared to uncoated carbide insert. From 1st and 2nd order regression model, 2nd order model explains about 98.3% and 86.3% of the variability of responses (flank wear and surface roughness) in predicting new observations compared to 1st order model and indicates the better fitting of the model with the data for multilayer TiN coated carbide insert. For ZrCN coated carbide insert, 2nd order flank wear model fits well compared to surface roughness model as observed from ANOVA study. The savings in machining costs using multilayer TiN coated insert is 93.4% compared to uncoated carbide and 40% to ZrCN coated carbide inserts respectively in hard machining taking flank wear criteria of 0.3 mm. This shows the economical feasibility of utilizing multilayer TiN coated carbide insert in finish hard turning. 相似文献