小直径深孔钻削监测系统

在对深孔钻削系统进行力学分析的基础上,针对小直径深孔钻钻头及钻杆直径小的特点,设计出一款用于小直径深孔加工监测系统的应变式传感器。     

深孔钻削工艺及深孔钻床

所谓深孔,目前尚没有一个确切的定义。一般认为孔深与孔径之比大于5～10,甚至到100或100以上的孔叫深孔。 一、麻花钻加工深孔的缺点 深孔钻削在很久以前以至于现在还没有使用深孔加工专用机床的厂家,都是用麻花钻进行钻削,这种加工方法存在下列缺点:     

不锈钢小直径深孔钻削

一、前言核电站设备的不少零件都需要进行深孔加工,这些零件的材料大都是难切削的耐热不锈钢00r18Ni9Ti、0Cr18Ni12MoTi等。因此在钻削一些直径小(8～12mm)、深径比大(100左右)的深孔时,加工难度相当大。加工中存在的主要问题是:     

深孔钻削过程中的智能控制

针对深孔钻削过程中出现切削扭矩异常变化导致钻头、钻杆损坏等问题,设计一套即时检测刀具扭矩、采用模糊控制方法控制钻削进给量的深孔钻削过程智能控制设备。介绍了系统的组成和原理。     

深孔钻削夹具

对于新产品加工,经常会出现原有设备不能满足生产需求的情况,但是,购置新设备或刀具将导致加工成本迅速上升,造成原有设备闲置甚至改变车间工艺布局,而设计开发适用的工装可以拓展设备能力,解决生产需要。本文针对产品结构特点,开发了旋转式钻模夹具,通过快速定位和夹紧装置,实现了精确加工和快速装卸,在普通钻床上完成了深孔新产品加工任务,解决了加工精度低、加工效率低和加工成本高等问题,同时,为企业节省了生产费用。     

小径深孔钻削钻头位置同步检测系统

针对加工小径深孔时检测装置无法放入深孔内部进行钻头位置检测和检测结果受工件表面形状影响较大的实际问题,提出了基于超声波检测技术和激光位移传感器检测技术的同步位移检测方法,建立了以PLC、上位工控机和同步检测装置组成的检测系统。设计了同步检测装置和检测系统,并对检测系统进行了分析。从而为提高小径深孔加工质量供了一种新检测技术,该系统能满足检测要求,对深孔钻头位置检测具有一定的前景。     

深孔钻削中油路系统静态特性分析

采用通用计算流体力学软件 FLUENT 对深孔钻削中油路系统进行力学仿真.仿真结果表明:试验仿真结果与理论结果相吻合,同时也找出在排屑过程中应该解决的主要问题(一方面是进油口处的压力和流量,另一方面是切削区钻头形状的改进),这些问题的研究对实际排屑问题的解决有指导性作用,并且使研究者更进一步形象地认识到处于封闭状态下深孔加工的特性.     

亚干式深孔钻削系统的研究

分析了对深孔切削加工现状,探讨了亚干式切削技术用于深孔加工的可能性和其方案设计、加工效果、应用前景.     

钛合金材料深孔钻削工艺研究

钛合金的切削加工性能差，尤其是钻削深孔的技术难度更大。这里通过对钛合金材料的切削性能和深孔钻削工艺的研究，设计出了一种专门用于钻削钛合金的深孔钻头，并通过一系列钻削试验表明，其工艺效果良好，有效地解决了钛合金材料的深孔钻削。     

超声振动精密深孔镗削试验研究

通过超声振动深孔镗削试验,研究了超声振动镗削时切削速度、进给量和背吃刀量对加工精度和表面粗糙度的影响规律,分析了精密深孔超声振动镗削时的切削机制.     

Novel micro deep drilling using micro long flat drill with ultrasonic vibration

This paper highlights the development of micro long flat drills with nominal diameter and flute length of 20 μm and 200 μm, respectively, by precision grinding. Furthermore, it also covers the evaluation of the developed micro long flat drill in micro deep drilling. Micro long flat drills were made of ultra-fine grained cemented carbide containing WC particles with an average particle diameter of 90 nm. First, the study focused on establishing the optimal web thickness of micro long flat drill showing the best performance in micro deep drilling. In drilling experiment, observation was conducted with the aim of finding the best conditions and method of micro deep drilling into both duralumin and stainless steel workpieces. This observation included the applications of ultrasonic vibration (USV) and step feeding method. The study proved that there was an optimum web thickness resulting in the best drilling performance. Furthermore, the application of USV during drilling could lead to a longer tool life significantly. However, there was no improvement of drilling performance in drilling with step feeding.     

中小孔径整体型高速钢深孔钻头的研制

针对焊接型硬质合金深孔钻头在中小孔径深孔钻削中使用寿命低，易损坏，修复和刃磨困难等缺点，研制成了一种整体型高速钢深孔钻头，使用效果令人满意。     

The effect of plasticity on the ability of the deep hole drilling technique to measure axisymmetric residual stress

Mechanical strain relief covers a class of techniques for measuring residual stress in engineering components. These techniques work by measuring strains or displacements when part of the component is machined away. The assumption is that such strain or displacement changes result from elastic unloading; however, in components containing high magnitudes of residual stress elastic–plastic unloading may well occur. Such elastic–plastic unloading introduces errors into the measurement of the residual stresses and these errors may be large. This paper addresses the performance of the deep hole drilling technique, a mechanical strain relief technique particularly suitable for large section components. First a plane strain analysis is presented that quantifies the errors associated with plasticity for different magnitudes of residual stress. A three dimensional finite element analysis is then carried out that shows larger errors may be obtained than those suggested by the plane strain analysis. A method for reducing the magnitude of the error is investigated. Finally, the results of an experimental measurement of residual stress are presented where substantial plasticity occurs. The work demonstrates the potential vulnerability of mechanical strain relief methods to plasticity and introduces methods for quantifying the resulting errors. It also provides further evidence that modifications to the standard DHD technique can be made to make the technique less susceptible to error when plasticity occurs.     

用高转速微电极电解钻削深小孔

针对难切削材料的深小孔加工,提出一种有效排屑、迅速补充电解液的新工艺——高转速微螺旋电极电解钻削加工工艺,并对该工艺进行了机理分析与试验研究。研究了电极转速、电压、脉冲频率、进给速度等工艺参数对深小孔电解钻削加工精度和稳定性的影响,提出合理匹配上述参数可在较高加工效率下获得高的加工精度和加工稳定性。基于硬质合金微螺旋电极用自行研制的高精度微细电解系统成功地在高温镍基合金GH4169上加工出了一组孔径小于0.5mm、深径比大于10、形貌较好,锥度较小,侧壁陡直,进出口边缘锐利的深小孔。试验结果表明,高速电解钻削加工工艺在深小孔加工方面很有潜力。     

超声波测厚系统的研究

深孔加工是一种封闭式或半封闭式状态下的加工,其加工过程很不稳定,深孔加工刀具的走偏现象直接影响被加工孔的直线度,造成被加工工件报废,所以在深孔加工过程中的实时检测就显得尤其重要.根据深孔加工系统的特点,将超声波测厚原理用于单管内排屑喷吸钻深孔加工在线监测中,通过检测被加工工件壁厚来判断刀具是否走偏,结果表明,该测试装置较好地解决了深孔钻削加工刀具走偏的监测问题.     

Use of process signals for tool wear progression sensing in drilling small deep holes

Detailed knowledge about the relation between wear progression of a cutting tool and the cutting forces generated is of paramount importance for the development of a tool condition monitoring strategy. This paper discusses the changes in the different process signals with progressing tool wear of small diameter twist drills (D=1.5 mm), when drilling boreholes having a depth of 10 times the diameter in plain carbon steel using MQL. The effect of different wear patterns on the process signals is presented. Furthermore, several features, which evolve over the life of the drills, are identified and extracted from the process signals. Knowledge about the evolution of these features can support the user to determine the final tool life stage, so that the drill can be replaced before the final fracture occurs.     

Surface quality evaluation in ultrasonic drilling through the Taguchi technique

Ultrasonic drilling of commercially pure titanium and titanium alloy (Ti-6Al-4v) was investigated in this study. During the experiments, process parameters such as work piece, grit size, slurry concentration, power rating and tools were changed to explore their effect on the surface roughness. Taguchi’s technique was applied to obtain an optimal setting of ultrasonic drilling (USD) process parameters. Average surface roughness (Ra) was measured by using the Optical Profiling System. Two-dimensional and three-dimensional contour plots were obtained from the profiling system to quantify and visualize the surface roughness. From the experimental results and further analysis, it is concluded that the effect of slurry concentration and grit size have a significant effect on surface roughness more than other parameters. In addition, the surface roughness is apparently similar in two and three dimensions as visualized from contour plots. Ultrasonic drilling is established as a material removal process with good surface quality.     

深孔测量装置的空间姿态和位置检测技术研究

针对深孔测量的理论和技术问题,介绍了一种用于深孔测量的测量装置,提出并证明了深孔测量装置的空间姿态和空间位置的检测算法,该算法通过安装在测量装置上的多个传感器的测量数据,计算出测量装置的空间位置和空间姿态,从而有效地解决了深孔检测中基准引入和内表面测试点空间定位的问题。     

高温镍基合金深孔加工

在分析难加工材料切削特性的基础上,针对高温镍基合金的深孔加工,设计一种在普通车床上使用麻花钻头进行深孔加工的工艺装备和工艺方法,提高了工作效率,并取得了良好的效果。