Design of a deburring tool for intersecting holes in aluminum alloys

A deburring tool for intersecting holes is proposed. The tool has a hemispherical cutter head mounted on a pivoted shaft which is loaded against the burr edge by a set of springs. The cutter head is inserted into an intersecting hole up to the burr edge and is subsequently rotated counterclockwise with a return stroke. The cutter head size is selected such that the cutter head has maximum accessibility to the three dimensional burr edge. The cutting edge is designed to maintain proper ranges of rake angle and relief angle during deburring. The efficiency of the tool in terms of deburring speed is verified by a set of deburring tests on Al6061-T6. The measured depth of cut on the burr edge confirms the complete removal of burrs.     

涡轮叶片气膜孔制造及检测技术发展与展望

涡轮叶片作为航空发动机最核心的热端部件,在叶身加工气膜冷却孔是提高叶片承温能力的必然趋势。目前主流制孔工艺方法包括电火花加工（EDM）、电化学加工（ECM）与激光加工。其中,电火花制孔工艺最成熟,成本效率优势最为明显,广泛应用于多种型号叶片;电化学制孔可以满足“无重熔层、无微裂纹、无热影响区”的孔壁质量验收要求,但对异型孔加工能力不足限制其应用前景;长脉冲激光主要应用于静子件及燃机叶片的制孔,近些年随着超快激光技术的迅猛发展,孔壁加工精度及质量得到显著提升,使其在叶片转子件的制孔中也获得应用。此外,采用磨粒流、磁力研磨等气膜孔后处理工艺可消除孔口相贯线锐边,避免应力集中效应导致锐边起裂。目前,气膜孔检测技术的工程化应用滞后于加工技术,但对于叶片制孔质量控制与验收标准制定具有重要意义,亟需建立相关标准将先进测试表征方法应用于工程生产中,并长期助力智能制造技术发展。     

振动研磨去喷孔毛刺实验

为了解决喷嘴的喷孔毛刺去除困难的问题,采用低频振动研磨去毛刺工艺进行去喷孔毛刺实验,由结果可以看出,该工艺方法能显著地去除喷孔的毛刺.且该低频振动研磨系统具有工艺易于实现、成本低且操作简便的特点.     

Wet blasting as a deburring process for aluminum

Light weight aluminum has shown high applicability in the automobile industry for high fuel efficiency. However, the manufacturing of aluminum is limited by the deburring process owing to the difficulty in employing wet blasting. In this paper, we present experimental and computational studies on the deburring process of wet blasting for aluminum. The process conditions are analyzed to achieve high deburring performance that minimizes the surface damage. Parameters of wet blasting with a significant influence on the deburring process are investigated and a promising deburring technique for aluminum is proposed.     

Deburring microfeatures using micro-EDM

Demands for miniature components are rapidly increased in the field of optics, electronics, and medicine. Various machining methods have been introduced for the fabrication of complex three-dimensional microfeatures. However, burrs, which are an undesired but unavoidable by-product of most machining processes, cause many problems in assembly, inspection, process automation, and precision component operation. Moreover, as feature sizes decrease, burr problems become more difficult to resolve. To address this problem, several deburring methods for microfeatures have been introduced, including ultrasonic, magnetic abrasive, and electrochemical machining methods. However, these methods all have some shortcomings, such as mechanical damage, over-machining, changes in the material properties of the finished surface, sharp edge blunting, and the requirement for subsequent processing to remove chemical residues. In this study, microelectrical discharge machining (micro-EDM) using low discharge energy and a small-diameter cylindrical tool is introduced for deburring microfeatures. This method allows the machining of very small amounts of conductive materials regardless of the material hardness, and provides easy access to small microscale features for selective deburring. The burr geometry generated by the micromilling process was investigated to establish a deburring strategy using micro-EDM. The proposed method was verified by experimental results using aluminum, copper, and stainless steel workpieces.     

板坯连铸锤刀式去毛刺机的结构改进

在线锤刀式去毛刺机驱动系统结构复杂及去毛刺率低,本文对去毛刺机的传动系统结构进行了改进,省去原有的液压抱闸、减速机,由驱动电机和万向连轴器直接连接,使结构简化;并将锤刀与长销轴的连接孔由原来的圆孔改为长孔,使锤刀在长销轴的竖直方向的伸缩量增大,提高了去毛刺率,减少了毛刺对辊道的划伤,提高了铸坯质量.     

喷丝板小孔电火花加工工艺研究

研究了喷丝板小孔的放电加工工艺和对应电极的制造技术,先用数控加工的方法制造电极,再用电极对小孔进行批量加工。通过优化电极结构、电极制造工艺以及小孔的放电加工工艺,缩短了总体加工时间,并保证了加工的安全性,提高了加工效率。     

Experimental analysis of deburring process on inclined exit surface by new deburring tool

The removal of macro-burrs formed after drilling has always been a difficult engineering problem, especially on inclined exit surfaces with intersecting holes. A new deburring tool is developed to remove burrs on inclined exit surfaces. The performance of the proposed deburring tool is analyzed according to changes in parameters including tool geometry, the deburring direction, and cutting conditions. Based on our analysis, proper tool geometry is suggested, and an efficient deburring method and deburring conditions are determined which satisfy the chamfered geometry and surface roughness of holes.     

TRIZ辅助便携式电解去小孔毛刺装置设计

针对中小批量工件内小孔毛刺去除成本高的现状,运用TRIZ理论对当前电解去毛刺加工装置存在的问题进行分析,建立电解去毛刺装置的功能结构并确定了各功能元的作用及连接关系。在此基础上,对工装夹具、电解液系统及装置壳体进行了创新设计,并完成加工电源的选型及控制系统设计。该装置操作方便、结构小巧、成本低廉、安全可靠。     

Micro electrochemical machining for complex internal micro features

In this paper, the application of micro electrochemical machining (ECM) for the micromachining of internal features is investigated. By controlling pulse conditions and machining time, micro features are machined on the side wall of a micro hole. These methods can easily machine a micro hole with larger internal diameters than the entrance diameter, which is very difficult to do by the conventional processes. A micro disk-shaped electrode with an insulating layer on its surface is also introduced to machine microgrooves inside the hole. This method is similar to the turning lathe process. The purpose of this study was to confirm the various possibilities of making complex internal structures in a micro hole by micro ECM.     

精密零件的微磨料气射流光整加工

近年来,在非传统去毛刺加工方法中,微磨料气射流去毛刺由于初始成本低、生产效率高、灵活性强、无应力、无热影响区,在精密零件的光整加工中获得了广泛的应用。本文详细介绍了微磨料气射流用于光整加工去毛刺的加工原理、材料去除机理、去毛刺的工艺参数以及对棱边尺寸的影响,并列举了一些微磨料气射流在不同应用领域的加工实例。     

针阀体喷孔脉冲电流电解去毛刺技术研究

在介绍针阀体喷孔去毛刺工艺方法的基础上,研究了针阀体喷孔脉冲电流电解去毛刺工艺和技术.采用该工艺对针阀体喷孔进行了倒圆实验和电解去毛刺效果流量测定.实验结果表明,经脉冲电流电解去毛刺后的针阀体较传统方法加工的针阀体喷孔流量明显提高,初始间隙较小时喷孔内入口处倒圆半径偏差明显减小.     

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.     

Machining of shaped holes using focused laser radiation

The process of manufacturing shaped holes in rotating blank parts using focused laser radiation is investigated. It has been revealed that a hole with a specified shape and cross section can be obtained by varying the inclination angle of the blank’s rotation axis and the laser machining modes.     

Precision machining of small holes by the hybrid process of electrochemical removal and grinding

This paper presents a hybrid process of grinding and electrochemical removal for machining of precision small holes with hard-to-machine materials. In the process, a metal rod with coated abrasives as cathode tool rotates at high speed and removes material electrochemically and mechanically for a pre-machined pilot hole. The effects of process parameters on the hole surface quality and dimensional accuracy were demonstrated experimentally. Material removals on grinding and electrochemical machining are well balanced by rationally determining machining voltage, tool rotation speed and feed rate. Precision holes of diameters down to 0.6 mm with sharp edges and without burrs have been produced.     

纯钼与纯钛电化学去毛刺实验研究

为消除由纯钼和纯钛加工成的待加工件表面出现的金属重熔层和毛刺,选用电化学去毛刺工艺来去除这些待加工件上的金属重熔层和毛刺。电化学去毛刺工艺利用电化学阳极溶解的原理去除间隙的毛刺,其具有对工件无机械力、与工件材料硬度无关等优点因此其在加工高硬度和高韧性的金属工件上有着天然优势。通过使用不同电解液,运用电化学去毛刺的加工手段分别测试用电火花线切割加工过的钼片和钛片的去毛刺效果,得到了在30℃的电解液温度和5V的加工电压以及5s的加工时长下,电化学去毛刺加工在对纯钼和纯钛的加工上有着很明显的效果的结果。     

飞机螺栓连接件制造偏差的应力集中及处理方法分析

飞机零部件在制造过程中会不可避免的出现偏差。通过分析孔位置偏差对螺栓连接件结构应力的影响,研究了不同边距下的多销荷载分布,得到了详细的应力分布和集中情况。在此基础上,结合超孔直径和堵孔材料厚度两个因素,分析了堵孔加工方法对应力集中的影响规律。这为利用公称应力法确定孔位置偏差零件应力集中引起的疲劳损伤的第一个位置以及用公称应力法估算孔位置偏差零件的疲劳寿命提供了基础数据支持。     

304Cu抗菌不锈钢热轧带钢边裂缺陷成因分析及改进措施

针对304Cu抗菌不锈钢热轧带钢边部开裂问题,通过微观组织及成分分布分析,对缺陷产生原因进行了研究。结果表明,304Cu热轧带钢边部裂纹分存在两种形貌,表面裂纹呈网格状,宽度约为30~70 μm,内部裂纹发生在表面下方1 mm范围内,内部裂纹中心存在20~40 μm孔洞,孔洞内部无非金属夹杂物等杂质。分析得到造成304Cu热轧带钢边裂的原因为Cr富集的高温铁素体与奥氏体基体发生高温组织不稳定变形,高温组织的不协调变形导致边部开裂。另外,Cu元素的富集降低了晶间结合力,也促进了内部孔洞的产生,进而加大了边裂缺陷的发生几率。因此,在保证冶炼成分稳定的条件下,通过调整热轧加热工艺,控制加热时间在190~210 min、加热温度在1 260~1 275 ℃的区间内,304Cu抗菌不锈钢热轧带钢边裂缺陷得到明显改善。     

弯管接头车床加工螺纹夹具设计

通过设计使用简单的夹具,解决了加工中的问题,提高了加工效率。利用零件本身的弯管部位和夹具上孔构成轴孔定位,利用零件本身的孔与夹具上削边销构成销孔定位,通过夹具使零件回转中心与车床回转中心重合,实现切削条件。夹具制造成本低,使用方便,有效保证了加工质量。     

Shaped tube electrochemical drilling of good quality holes

This paper is concerned with the shaped tube electrochemical drilling (STED) of small diameter cooling holes in turbine blades. Following an initial identification of the common defects occurring in STED, a partial factorial design of experiments (DOE) was carried out to identify the more important process parameters that affect hole quality. For these process parameters, a full factorial design of experiments was conducted to study their effects not only on hole diameter but also on hole taper. Guidelines and equations for determining appropriate operating conditions to drill a good quality hole are presented for one drill diameter.