微细轴切削加工特性分析

分别采用传统的车削方法和先进的车铣方法进行微细轴的切削加工试验,从切削方式、切削速度、切削力等9个方面对两种切削方法进行了比较。试验结果表明,车铣技术更适合于微细轴类零件的加工,它在改善微小型零件的切削状态、实现高速切削、降低切削力、延长刀具寿命、保证零件加工质量、提高加工效率等方面都具有明显优势,只要合理匹配车削主轴与铣削主轴的转速比,同时合理辅以其他切削用量,就可以加工出理想的微小型零件。     

微细轴加工技术

高精度的微细轴加工技术是产品小型化发展的基础.通过对微细轴切削加工和电加工技术的原理分析,对两种技术在微细轴加工方面的特点进行了归纳,并给出国内外应用切削加工技术和电加工技术加工微细轴具有代表性的实例.     

基于车铣复合加工技术的微细丝杠切削研究

车铣复合加工技术能实现以铣代车或磨高速切削回转体零件。基于此技术的微细切削无论是在生产率还是在加工表面质量上,较其它加工技术而言,更适合于微细轴类零件和具有复杂型面的微小型零件的加工。通过微细车铣切削微细丝杠试验,从切削用量和加工质量及刀具磨损方面研究了车铣复合加工技术在解决微细丝杠加工中的应用。结果表明,基于车铣复合加工技术能够实现微细丝杠的高速切削。该技术非常适合于微细丝杠零件加工。     

细长轴的切削加工精度及切削效率的控制研究

细长轴广泛应用于各种机械当中,但细长轴的长径比一般都大于25,故在加工时存在一定的困难。通过对细长轴应用场合的介绍,对切削加工时的误差来源进行了介绍,并分析了细长轴弯曲变形的原因,从而提出了在保证细长轴精度的同时,如何提高其切削效率的方法。     

切削温度对微细切削加工影响的有限元分析研究

建立微细切削仿真模型,对二维正交切削加工过程进行了热力耦合有限元数值分析,采用有限元模拟与微细切削加工实验验证相结合的方式,深入研究了切削温度对微细切削加工的影响,揭示了在高速、大切厚加工条件下,随着切削厚度的减小,刀—屑接触区切削温度降低,增加了材料的截切强度,从而引起材料的强化,导致单位切削力显著增加。     

长径比大于80的细长轴类零件的切削加工工艺

对于长度与直径之比(长径比)大于80的细长轴,在切削过程中由于其刚性差而极易产生弯曲和振动,难以获得良好的加工精度和表面粗糙度。且热扩散差,线膨胀大,当工件两端顶紧时受热变形影响易产生弯曲,因此,长径比大于80的细长轴是轴类零件中较难加工的零件。在实际生产中,可通过采用三支承跟刀架、弹簧顶尖、改进刀具的几何角度或采用宽刃精车刀、选择热硬性好及高耐磨的刀具材料、增设合理的辅助工具等方法达到满意的加工效果。     

超微细切削加工质量影响因素及对策

精细切削加工主要是指对零件尺寸在1mm以下、加工精度为0．01—0．001mm的微细尺寸零件的加工;微细切削加工是指对尺寸在1μm以下的微细零件的加工;超微细切削加工是指对微细度为1nm以下的零件进行的加工。     

四轴零件特征及其典型零件的数控加工

分析了四轴零件的结构特征、工艺特点以及应用场合,融合四轴加工策略,编排了典型四轴零件的数控车削和数控铣削的复合加工工艺,并完成了零件的数控编程和加工。     

密珠芯轴的应用及其精度对被加工零件的影响

密珠芯轴的应用及其精度对被加工零件的影响一般孔定位的套类零件在加工时，常采用间隙配合的端面夹紧心轴，对于精度要求较高的通孔套类零件，可使用锥度较大的锥度心轴进行加工。但对于图１中的零件来说，显然锥度心轴和普通心轴是无法完成的。对于这类零件，我们通常采...     

微细切削加工与微机械制造

介绍了微机械制造中的切削加工方法及设备的研究进展情况，包括微细车削、微细钻削、微细铣削、微冲压及微型工厂等。这些技术加工的工件都已经达到了微米尺度，它们在微三维结构的制造方面有独特的优势。     

数控加工普通螺纹切削深度的计算与修正

分析了使用数控车床加工普通螺纹时，关于螺纹切削总深度的计算与修正，探索在螺纹车刀刀尖圆孤半径R变化的情况下，螺纹切削总深度K值的计算新方法，以保证螺纹的加工质量。     

An Experimental Study to Enhance the Cutting Performance in Abrasive Waterjet Machining

An experimental study to enhance the cutting performance in abrasive waterjet (AWJ) machining is presented. The study uses the techniques of jet forward impact angles and multipass operations both individually and concurrently when cutting an alumina ceramic and a polymer matrix composite. A brief report on the effect of jet impact angle in single pass cutting is made first, which shows that the optimum jet impact angle for both the ceramics and polymer matrix composite is about 80°. It is found that the multipass cutting technique can increase the cutting capability and application domain of AWJ cutting. It can also improve the major cutting performance such as the depth of cut as compared to single pass cutting within the same total cutting time. The benefit of using multipass cutting operations is further enhanced when it is combined with a jet forward angle of 80° in cutting alumina ceramics.     

精密加工中切削参数对毛刺尺寸的影响

毛刺的产生是金属切削加工中长期存在的问题,在实验的基础上通过对精密车削中进给方向毛刺的研究,分析了切削参数对毛刺尺寸的影响,为毛刺生成机理的研究以及毛刺的抑制和去除做了部分基础性工作。     

高速加工理论在普通数控机床上的应用

高速加工在切削速度、材料去除率以及表面加工质量等方面较普通数控加工具有明显优势。在工艺研究中,将高速加工切削理论应用在现有的普通数控设备上,在主轴转速不变或相应提高的情况下,提高切削移动速度同时减小切削深度进给量,从而达到提高切削效率、减小切削应力以及改善加工表面质量的目的。     

铝基复合材料精密加工试验研究

文中通过采用PCD刀具进行SiCW增强铝基复合材料的精密切削试验，用原子力显微镜AFM对加工表面的微观形貌进行检测分析，表明SiCW／Al复合材料的加工表面粗糙度值可以达到精密级，但比切削铝基体材料获得的表面粗糙度值更大，且粗糙度值随着切削速度的增加、进给量的减小而减小，而与背吃刀量的关系不大。     

复杂微小型工件的完整加工工艺分析

微小型工件的再装夹和定位是非常困难的,为了提高微小型工件的加工精度和加工效率,实现完整加工是解决问题的方法之一。车铣加工技术具有实现完整加工的能力。在分析了高速车铣加工中心实现复杂微小型工件完整加工的工艺过程的基础上,通过加工实例证明了车铣加工技术能方便地实现以回转体为基体的复杂微小型工件的完整加工。     

精密加工和超精密加工技术综述

论述了精密加工和超精密加工技术的范畴,加工方法,系统结构及其在先进制造技术中的作用和地位;分析了２１世纪初期对它的需求和技术发展趋势,并提出了相应的技术发展前沿,归总了技术发展特点。     

顺逆混合铣-铣复合加工方法的切削力分析

难加工材料已广泛应用,但加工过程中出现了的切削力大、刀具寿命短等诸多问题,提出了在不降低材料去除率的前提下有效地降低切削力的大小的新方法铣-铣复合加工方法,顺逆混合铣-铣复合加工方法是铣-铣复合加工方法的一种形式,顺逆混合铣-铣复合加工方法中的刀盘在低转速下就能实现高速切削。顺逆混合铣-铣复合加工方法中将总磨损量平均到了不同立铣刀的不同的切削刃上从而提高了整个刀具的寿命,从方法上解决了难加工材料加工中刀具寿命短的难题。实验结果表明顺逆混合铣-铣复合加工方法发挥了铣-铣复合加工方法组合优势,部分切削力能够相互抵消,从而减小加工工件的受力。     

An Experimental Study and Statistical Analysis of the Effect of Laser Pulse Energy on the Geometric Quality During Laser Precision Machining

In laser precision machining, process parameters have critical effects on the geometric quality of the machined parts. Due to the nature of the interrelated process parameters involved, an operator has to make a host of complex decisions, based on trial-and-error methods, to set the process control parameters related to the laser, workpiece material, and motion system. The objective of this work is to investigate experimentally the effect of laser pulse energy on the geometric quality of the machined parts in terms of accuracy, precision, and surface quality. Experimental study of formation of machined craters on thin copper foil with variation in laser pulse energy, the geometry and the surface topology of craters is presented. The geometrical parameters were measured and statistically analyzed with respect to incident pulse energy. Statistical analysis including pattern recognition was employed to analyze the experimental data systematically and to serve proper selection of the process parameters to achieve the desired geometric quality of the machined parts. Plausible trends in the crater geometry with respect to the laser pulse energy are discussed. The technique has been verified experimentally on simple geometrical features such as circles and grooves, and the geometric quality is evaluated.     

An Experimental Study and Statistical Analysis of the Effect of Laser Pulse Energy on the Geometric Quality During Laser Precision Machining

In laser precision machining, process parameters have critical effects on the geometric quality of the machined parts. Due to the nature of the interrelated process parameters involved, an operator has to make a host of complex decisions, based on trial‐and‐error methods, to set the process control parameters related to the laser, workpiece material, and motion system. The objective of this work is to investigate experimentally the effect of laser pulse energy on the geometric quality of the machined parts in terms of accuracy, precision, and surface quality. Experimental study of formation of machined craters on thin copper foil with variation in laser pulse energy, the geometry and the surface topology of craters is presented. The geometrical parameters were measured and statistically analyzed with respect to incident pulse energy. Statistical analysis including pattern recognition was employed to analyze the experimental data systematically and to serve proper selection of the process parameters to achieve the desired geometric quality of the machined parts. Plausible trends in the crater geometry with respect to the laser pulse energy are discussed. The technique has been verified experimentally on simple geometrical features such as circles and grooves, and the geometric quality is evaluated.