共查询到16条相似文献,搜索用时 153 毫秒
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GFRP的套孔钻削过程中极易产生分层、撕裂等加工损伤,其与轴向钻削力直接相关。为提高GFRP的制孔质量,采用新型金刚石薄壁套料钻,结合低频轴向振动加工技术,建立单颗磨粒的运动学模型和动力学模型,试验研究GFRP制孔中的轴向力变化规律,并对套料钻的烧焦概率、自动落料率进行分析。结果表明:对比常规钻削,低频振动钻削时的瞬时进给量和轴向力比常规钻削时的大,且随着振幅的增加,轴向力也随之增大;低频振动钻削和常规钻削时的轴向力皆随进给速度的增加而增大,随主轴转速的升高而降低。同时,低频振动钻削时磨粒间断性地参与钻削,大大降低了套料钻的烧焦概率,提高了其自动落料率,自动落料率高达88.24%,可实现GFRP的连续批量制孔。 相似文献
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深孔钻削中常出现走偏、折断钻头等现象,严重影响深孔质量.文章深入分析了深孔加工中的各种力学关系,研究了切削力系、附加力系、挤压力与挤压力矩、摩擦力与摩擦力矩等与走偏、折断钻头之间的关系,找出了一些带规律性的问题,趋利避害.经大量试验,获得到了钻具受力与孔径、力矩与孔径及不同材质情况下的切削功率与进给量等切削参数之间的相关数据.通过采取导向装置、预钻引导孔等技术措施进行深孔钻削.应用结果表明,深孔钻削的受力情况得到了明显改善,深孔精度与加工效率显著提高. 相似文献
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《组合机床与自动化加工技术》2020,(8)
采用DF系统钻削深孔时,断屑是影响钻削质量的关键要点与难点。文章将DF系统与振动钻削结合起来,通过对其断屑理论的研究,得出了DF系统振动钻削在有、无振幅损失时的完全几何断屑条件。基于Defrom-3D软件对DF系统振动与传统钻削的切屑形态进行了数值仿真对比试验。并通过加工实验,验证分析了振动与传统钻削各自的断屑情况,探讨了振动钻削在使用不同参数时的钻削效果。结果表明:DF系统振动钻削比传统钻削断屑更为可靠,且选用不同参数可控制切屑的形态。 相似文献
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Feasibility study of the ultrasonic vibration assisted drilling of Inconel superalloy 总被引:4,自引:0,他引:4
Y.S. Liao Y.C. Chen H.M. Lin 《International Journal of Machine Tools and Manufacture》2007,47(12-13):1988-1996
The ultrasonic vibration assisted drilling of Inconel 718 superalloy is studied in this paper. The tool holder of a machining center is retrofitted so that axial resonant vibration can be provided. Experimental results show that the chip size is reduced, and the variation of torque in drilling becomes smaller. These phenomena are particularly apparent at the final stage of a drill's usable life. It is also found that there is little improvement in drilling performance when the frequency of the ultrasonic vibration is varied. On the contrary, a drill's life is greatly increased when the vibration with a smaller amplitude is applied. But too large a vibration amplitude, such as over 12 μm in this study, could lead to negative effects. For the testing conditions, the frequency of 31.8 kHz and the amplitude of 4 μm result in the best drill life and quality of the drilled hole in this study. Under this condition a drill's life is prolonged by as much as 2.7 times of that without vibration assisted drilling process. Concerning drilling efficiency, it is found that by applying ultrasonic vibration assisted drilling, lifting of the drill for chip removal as commonly employed in conventional drilling of a high aspect ratio hole is not necessary, and saving of the working time is obtained. 相似文献
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Feasibility study of the rotary ultrasonic elliptical machining of carbon fiber reinforced plastics (CFRP) 总被引:3,自引:0,他引:3
Jing Liu Deyuan ZhangLonggang Qin Linsong Yan 《International Journal of Machine Tools and Manufacture》2012,53(1):141-150
Carbon fiber reinforced plastics (CFRP) are used for various aircraft structural components because of their superior mechanical and physical properties such as high specific strength, high specific stiffness, etc. However, when CFRP are machined, rapid tool wear and delamination are troublesome. Therefore, cost effective and excellent quality machining of CFRP remains a challenge. In this paper, the rotary ultrasonic elliptical machining (RUEM) using core drill is proposed for drilling of holes on CFRP panels. This method combines advantages of core-drill and elliptical tool vibration towards achieving better quality, delamination free holes. The cutting force model and chip-removal phenomenon in ultrasonic elliptical vibration cutting are introduced and analyzed. The feasibility to machine CFRP for RUEM is verified experimentally. The results demonstrate that compared to conventional drilling (CD), the chip-removal rate has been improved, tool wear is reduced, precision and surface quality around holes is enhanced, delamination at hole exits has been prevented and significant reduction in cutting force has been achieved. 相似文献