薄壁长筒零件深孔镗削工艺与数控组合机床设计

文章对薄壁长筒类零件内孔镗削方法进行了分析,并设计了深孔镗削数控组合机床.同时机床的布局及主轴箱、弹簧夹头、深孔镗刀等关键部件进行了详细介绍.该机床的成功研制,解决了薄壁长筒零件深孔加工的难题,通过更换数控加工程序,更换夹头及刀具,调整液压中心架和导向架的轴向位置,该机床可以实现不同尺寸薄壁长筒类零件的内孔加工,运行效果良好.     

大型缸筒类零件孔加工方法研究与应用

针对大型缸筒类零件孔的加工方法,从工艺方案选择、静压中心支撑装置、高刚性孔加工专用刀杆设计以及切削参数选用等方面进行了系统性的分析,确定了合理的工艺方法,为大型缸筒类零件的加工提供了新的思路和方法。     

异型深孔内腔曲面加工装置的分析与研究

为了解决现代深孔加工技术领域中具有复杂内腔曲面的异型深孔零件难以加工的问题,以连铸结晶器内腔曲面为例,针对复杂内腔曲面的加工工艺进行了深入研究,并创新设计与研制开发了一套用于异型深孔内腔曲面机械加工的装置。利用ANSYS Workbench对装置进行了振动特性分析,得到了其固有频率和关键件的变形频响函数曲线,保证装置在远离可能发生共振区域的频率内稳定运行。该装置弥补了国内外在异型深孔加工领域中的不足,具有推广应用价值。     

差速齿轮进给机构的组合镗孔装置

我厂设计制造的一种差速齿轮进给机构的组合镗孔装置(图1),具有结构简单、使用方便、制造周期短等优点。现主要用于加工195型柴油机缸体、连杆和正时齿轮室盖等零件。经过两年多的使用实践证明效果良好,镗孔精度可达二级,光洁度可达6。这种装置可以用来进行各种零件的孔加工,尤其适合于小批量零件的加工。     

内孔反向组合刀具的设计及应用

采用内孔反向组合刀具,一次装夹就可以加工同轴度要求很高的两侧台阶内孔套类零件,特别是内孔孔径较小的套类零件,大大提高了此类零件的位置精度,加工效率高、操作方便。     

深孔侧壁冲孔模设计

介绍了一种深孔侧壁从里向外冲孔的模具,解决了深孔内毛刺难以去除的问题。模具结构新颖,冲孔凸模更换方便,模具已应用于批量生产,使用效果良好,加工零件质量稳定,可为类似零件的加工提供一定的参考作用。     

深孔类零件的工装设计及刀具改进

针对深孔类零件的加工要求,分析工件的装夹和定位,同时给出其夹具的设计,并针对该零件的加工要求,从不同方面分析刀具选用,有效地解决了原加工方案的加工效率低、成本高等问题,最后提出了提升刀具性能的方法及检测环节注意事项。     

深孔内壁盲孔加工装置设计及试验研究

深孔内壁盲孔是深孔加工中的工艺难点。针对深孔内壁盲孔的结构特点,在分析以往加工方法的基础上,设计一种新型的深孔内壁盲孔加工装置。介绍该装置的设计理念以及工作原理,建立装置的设计模型、钻头部分的力学模型。并用装置进行几种典型材料的工艺试验,证明该装置的加工可行性;分析加工所存在的问题以及影响加工精度的因素;针对试验结果提出装置的不足之处以及改进措施,为以后的改进提供重要数据。     

外悬式侧冲孔模设计

介绍了外悬式侧冲孔模结构及工作过程,大尺寸零件侧壁孔使用小吨位冲床进行加工,孔的位置尺寸可以保证。实践证明:模具操作方便,效率高,为同类零件的加工提供了一定的参考。     

通用薄壁类零件柔性夹具设计

薄壁类零件装夹及加工变形是夹具设计中需要重点考虑的问题。根据薄壁类零件的装夹特点,设计一种通用薄壁类零件柔性夹具,该夹具利用独特的径向支撑机构及对间隔环的灵活应用,可以实现对内径不同、长度各异的各种薄壁类零件的柔性装夹,有效克服薄壁零件在切削加工过程中的加工变形及装夹变形,从而保证零件加工质量的稳定性和生产效率的提高,且具有夹紧可靠、零件拆装方便、使用寿命长等特点。     

和田青玉超声波深孔高速钢麻花钻钻削试验研究

基于和田玉特殊的物理性能,采用直径为2、1.5、1 mm的高速钢麻花钻,在其主轴转速为700、1500、1800r/min;进给量为3μm/r和5μm/r的情况下;分别进行附加超声波振动和不附加超声波振动加工试验;在钻削加工过程刀具磨损,扩孔量、孔内表面粗糙度三个方面进行对比分析,超声振动波钻削能获得更好的加工质量和效率,并能减少钻头的磨损和破坏,为和田玉精密加工提供了一种新的深孔加工工艺方法。     

Accuracy estimation of drilled holes with small diameter and influence of drill parameter on the machining accuracy when drilling in mild steel sheet

The miniaturization of component parts has advanced in the modern industrial product sector. Corresponding with this new wave, there is a strong demand for the establishment of minute-scale techniques to manufacture products with high quality involving the drilling of small holes. Non-traditional machining techniques such as electro discharge machining can be applied to make small holes. However, there is much practical value if small holes can be made by the traditional drilling process. In this paper, a method for estimating the drilled hole accuracy using a Fourier series analysis is proposed and this method is applied to small holes 1 mm in diameter drilled in mild steel for machine structure use. As a result, it is clarified that the bending rigidity of drill and the thinning of the drill point exert a large influence on the drilled hole accuracy.     

Electro-spark coatings for enhanced performance of twist drills

Surface engineering approaches are being increasingly employed for enhancing the effective life of twist drills with a view to reduce machining costs. The electro-spark coating (ESC) technique provides a promising means of depositing wear resistant coatings that can potentially enhance the performance of these tools. However, it is often necessary to also optimize the machining conditions for coated tools to achieve an enhanced tool life. In the present investigation, varying spindle speeds were employed at a fixed vertical feed to evaluate the performance of WC-8Co ESC coated HSS drills in comparison to bare HSS drills. The number of holes drilled before reaching a preset average flank wear (0.5 mm), or catastrophic failure of the drill, was taken as the measure of tool life. The drill flank wear, monitored at regular intervals, as well as the cutting torque and thrust measured for all holes, were considered to be the key criteria for optimizing the cutting conditions. Results indicate that the WC-8Co coated drill tool life can be increased by a factor of more than 5, depending on the machining conditions selected. Furthermore, flank wear of the drill was found to increase rapidly at the end of drill life. Cutting torque data was also found to provide a useful indicator for predicting the end of tool life.     

Generalized groove-type chip breaker effects on drilling for different drill diameters and flute shapes

This paper proposes a generalized formulation to place chip-breaker grooves on drills of varying diameters. To verify the effectiveness of this generalization the groove is placed on the drill rake face of 6.35 and 3.18 mm diameter drills of standard and parabolic flute shapes using a fabrication process utilizing electro-discharge machining (EDM). The results indicate that chip size is reduced. The robustness of the placement of the groove is assessed with experiments validating effective distance from the cutting lip and groove depth thereby facilitating drill regrinding. Experiments are also conducted to study chip clogging when the chip-breaker groove is employed on small drill diameters.     

大直径簿壁零件径向钻孔加工

阐述零件12-φ20 mm孔加工难点,提出创新方案,设计支撑支架,利用万向钻床,设计制造扩孔钻头,成功解决了加工难度,加工质量基本合格,加工效率有所提高。     

混合铝基复合材料钻削工艺参数的优化(英文)

采用Taguchi方法和灰色关联分析对Al356/SiC-云母混合金属基复合材料的钻削工艺参数进行优化。实验采用L18正交阵列,在计算机的控制立式机床上进行。考察的钻削性能指标包括轴向力、表面粗糙度、刀具磨损和毛刺高度,对影响这些性能的钻削工艺参数进行了优化,包括轴转数、给进速度、钻头类型和云母质量分数。结果表明:给进速度和钻头类型是影响钻削过程的重要因素,通过这种方法可以有效地改进钻削工艺的性能。     

一种新型螺旋面钻尖刃磨机床的运动学研究

螺旋面钻尖在钻削的稳定性和自动定心上要优于普通钻尖。研究了利用并联机构的两轴联动来实现了螺旋面钻尖刃磨的新方法,对并联机构的运动学进行研究,基于MATLAB进行了运动学和工作空间的仿真。仿真结果表明,并联机构的运动特性符合刀具刃磨所需的运动特性,且X向工作空间对参数的变化更敏感。     

Small-hole drilling in engineering plastics sheet and its accuracy estimation

In recent manufacturing processes, the small diameter hole drilling process is frequently used owing to its good characteristics. The drilling process can easily be adapted to wide variations in lot size, processing accuracy, processing spot patterns where holes are made, and so on. Many machine elements, which have small diameter holes, are manufactured using engineering plastics of superior material and machining properties. However, it is not easy to drill holes with a diameter smaller than 1 mm, in recent machining technology as well. In this report, 1-mm diameter holes are drilled on two engineering plastics sheets and their drilling accuracy is discussed.     

Ultrasonic deep hole drilling in electrolytic copper ECu 57

At present the machining of highly ductile electrolytic copper ECu 57 with gun drills is carried out at very low feed values, as the material tends to form very long and unfavourable chips. In addition, high frictional forces on the guide rails cause high torsional strain on the gun drill. This paper first reports on the results of ultrasonically assisted deep hole drilling in ECu 57 with tools of 5 mm diameter. The actuator system for exciting axial vibrations in the ultrasonic range is described and experimental results which were obtained from cutting tests are reported. Particular emphasis is put on the improvements compared with the conventional drilling technology without superimposed vibrations. The effect of different input amplitudes is investigated in detail. The performance criteria are drilling moment, surface quality, chip form as well as the surface zone. By optimising the vibration amplitude, cutting speed and feed, the machining result was improved compared with conventional machining, and at the same time the stability of the machining process was simultaneously increased.     

钻套使用寿命分析

钻套作为钻床夹具的特征元件之一,主要起引导刀具的作用,它在使用过程中的磨损对零件加工精度的影响很大.通过一个实例分析,研究钻套使用寿命的计算方法,并提出提高钻套使用寿命的有效方法.