煤层塌孔修复装置自进钻头关键参数研究

在松软煤层进行瓦斯抽采时,钻孔中经常出现塌孔、堵孔等现象,基于此,提出采用自进钻头修复失效钻孔的新方法。基于牛顿定律和伯努利方程等理论,建立了自进钻头自进力的计算模型,通过最大钻进距离试验,验证了运动方程。将修复装置应用于余吾煤矿N1100回风顺槽,试验结果表明：该装置能够满足煤层塌孔修复的工程需要,瓦斯抽采浓度和流量均明显提高,修复效果明显。     

以改进抽放方法提高抽放效果的分析

基于瓦斯抽放概念,介绍了瓦斯的传统抽放方法,即地面钻井预抽煤层瓦斯、利用采动泄压抽放煤层瓦斯、采空区瓦斯抽采和煤层瓦斯预抽,并重点分析了底抽巷抽放瓦斯方法。分析认为,煤矿为了治理瓦斯,一般采用多种抽采方法综合治理瓦斯,即综合治理,以取得良好的生态经济效益。     

宽翼片螺旋钻杆的设计与实践应用研究

根据煤层瓦斯地质条件,选取合适的螺旋钻进工艺能很好地解决松软破碎煤层瓦斯抽采钻孔存在易塌孔、孔深浅、成孔难等问题。分析了螺旋钻具的结构特点和施工工艺的优缺点,结合螺旋钻具的排粉原理,推荐在松软破碎煤层中施工风水联动雾化排粉工艺和孔内全程下筛管工艺,可以有效解决松软煤层钻孔施工的难题。     

低透气性煤层顺层钻孔有效抽放半径测定

五矿贵石沟井由高瓦斯矿井变为煤与瓦斯突出矿井后,按照相关规定在15号煤层具有突出危险性的区域必须采取钻孔预抽措施,钻孔预抽效果的好坏取决于抽放半径是否合理,阳煤五矿需要尽快查明15号煤层顺层钻孔的有效抽放半径。通过在四采区8421进风顺槽内,采用钻相对压力指标法对矿井15号煤层抽采半径考察工作,对瓦斯压力下降曲线进行拟合,得出在抽放时间为73 d内,采用Φ75mm钻头施工钻孔对15号煤层进行抽放。试验结果显示:有效抽放半径可以达到1.5 m;当抽放时间为90 d时,抽放影响距离可达5.5 m,有效抽放半径为1.8 m,抽采钻孔间距取3.6 m较为符合五矿15号煤层实际情况。     

煤矿瓦斯抽放设备选型

煤炭井下开采作业,煤层中赋存的瓦斯气体会逸出,给安全生产带来隐患,有效地抽放瓦斯,是保障矿井安全生产的必要措施。瓦斯抽放主要依靠于设备,从瓦斯抽放方式、管路系统、设备选型、瓦斯抽放站等方面进行了分析。     

新型矿用注浆封孔机的设计与研究

为了确保煤矿安全生产,需要在煤层的开采过程中测定煤层瓦斯压力以及抽放瓦斯。钻孔的封堵质量好坏直接影响着瓦斯压力测定和瓦斯抽采的效果。新型矿用注浆封孔机采用手一电双动力方式对瓦斯抽放孔、测定孔进行封堵。通过设计要求的参数利用最jJ~--乘法计算出曲面零件的拟合曲线,拟合曲线的零件能够有效降低设备工作时柔性冲击和整体振动。试验表明新型注浆封孔机注浆压力高、封堵效果好且操作简单、安全方便,可广泛应用于矿井钻孔的封堵及建筑结构的裂缝填补等方面。     

工作面本煤层抽放钻孔喷浆注浆提高抽采浓度技术研究

以山西阳泉煤业(集团)有限责任公司三矿5号煤层瓦斯抽放效果为主要研究对象,阐述了目前矿井的瓦斯参数基本情况,主要从喷浆注浆对钻孔瓦斯抽采的影响进行分析,根据现场本煤层抽放过程中喷浆及喷浆工艺的选择进行探讨。研究表明,喷浆注浆工艺能够显著提高煤层钻孔的瓦斯抽采效率。     

对新元煤矿3号煤瓦斯综合抽采技术的研究

根据新元煤矿3号煤瓦斯涌出的特点,结合同类矿井的抽放经验,通过采用本煤层预抽、上邻近层瓦斯抽放、综掘工作面瓦斯抽放等方法,有效地解决了各种瓦斯超限问题,对矿井的安全生产有着重大意义。     

煤层瓦斯抽采排水装置的设计与应用

针对山西潞安集团古城煤业有限公司为解决煤层抽放的瓦斯中水分含量高、人工排水难度大、瓦斯利用率降低等技术难题而设计的一套煤层瓦斯抽采排水装置,分析其结构及工作原理、特点,及其在N1303工作面瓦斯抽采中的应用效果。实践证明取得了显著成效。     

瓦斯抽采钻孔修复设备的研究与应用

由于井下瓦斯抽采钻孔在采掘过程中容易受到冒落岩石破坏,经常发生塌孔、堵孔的问题。为实现对已施工抽采孔的高效重复利用,故借助瓦斯抽采孔水力作业机,利用高压水射流技术,将孔内堵塞杂物冲出,同时,扩大了抽采空与煤体接触的面积,使得煤岩层卸压,增大了煤体孔隙率,又使得瓦斯卸压、积聚,在抽采孔负压的作用下被顺利采出。延续使用已施工抽采孔,节省了重新打钻孔的多余支出。并现场进行试验验证,结果表明:经过水力作业机的修复增透技术,瓦斯抽采浓度和抽采纯量大大提升,抽采纯量是修复前的8倍以上,极大地改善了瓦斯抽采的效果和抽采率。     

Analysis of silicon via hole drilling for wafer level chip stacking by UV laser

For stacking wafers/dies, through-silicon-vias (TSVs) need to be created for electrical connection of each wafer/die, which enables better electrical characteristics and less footprints. And for via hole processing, chemical methods such as DRIE (Deep Reactive Ion Etching) are mostly used. These methods suffer the problems of slow processing speed, being environment-unfriendly and damage on the existing electric circuits due to high process temperature. Furthermore, masks are also needed. To find an alternative to the methods, researches on the laser drilling of via holes on silicon wafer are being conducted. This paper investigates the silicon via hole drilling process using laser beam. The percussion drilling method is used for this investigation. It is also examined how the laser parameters- laser power, pulse frequency, the number of laser pulses and the diameter of laser beam- have an influence on the drilling depth, the hole diameter and the quality of via holes. From these results, laser drilling process is optimized. The via hole made by UV laser on the crystal silicon wafer is 100μm deep, has the diameter of 27.2μm on the top, 12.9μm at the bottom. These diameters deviate from the target values by 2.8μm and 0.4μm respectively. These values correspond to the deviation from the target taper angle of the via hole by less than 1°. The processing speed of the laser via hole drilling is 114mm/sec, therefore, etching process can be replaced by this method, if the number of via holes on a wafer is smaller than 470,588. The ablation threshold fluence of silicon is also determined by a FEM model and is verified by experiment.     

一种在Z3040钻床上加工较长工件孔的方法

在液压油缸缸体法兰盘上加工螺纹连接孔(系),常在普通摇臂钻床进行,但对于较长工件端面上的螺纹连接孔(系)的加工,普通摇臂钻床则受到其最大升降距离的限制,难以进行.介绍了一种在小型摇臂钻床上加工较长工件上的孔的方法,可在Z3040摇臂钻床上加工较长工件端面上的孔,方法简单实用.     

超声振动辅助三尖钻钻削皮质骨的研究

在临床中,使用医用麻花钻给骨钻孔是常见的治疗手段,但医用麻花钻通常存在定心能力差的问题,骨大多都是曲面,所以在骨钻削中极易造成孔位的偏离、孔形不圆、孔直径偏大等现象。针对这一问题,改用定心能力更好的三尖钻并施加超声振动对皮质骨进行钻削研究。通过研究发现三尖钻超声振动辅助(UAD)钻削不仅改善了给骨钻孔时定心能力差的问题,而且与三尖钻普通(CD)钻削对比发现,UAD三尖钻钻削在轴向力、钻削温度、孔内壁表面粗糙度均比CD钻削有大幅度减小,钻孔直径精度则有大幅提高。三尖钻UAD钻削大幅度提高了孔的表面质量。     

异质多元多层印制电路板精密孔机械加工

孔是实现印制电路板层间互联及电子元器件装配的核心组成单元,机械钻孔是印制电路板制孔的主要方法。要在印制电路板上进行高密集度孔群的连续可靠、高质量、高一致性和高稳定性加工非常困难,涉及的异质多元多层复合材料机械加工理论复杂,也对加工刀具、加工技术提出了严峻挑战。从机械加工的角度归纳了典型印制电路板分类、组成结构与热力学特性,并提出其机械钻孔加工面临的难点;从材料变形与断裂、钻削热、钻削力与扭矩、孔创成机理、刀具失效机制五个方面,总结了典型印制电路板钻削理论的最新进展,综述了印制电路板用钻头设计、钻孔加工工艺和钻削过程检测技术的研究现状,从印制电路板微孔钻削加工理论、微细刀具优化设计、低温介质辅助钻削加工与孔质量无损检测方面指出了现有研究存在的问题,并结合新一代高端印制电路板发展趋势与孔制造需求,提出了未来印制电路板孔加工研究应重点关注的方向。     

BTA深孔切削直线度分析

随着孔深的增加,孔的直线度将有所下降.针对BTA(Boring and Trepanning Association)深孔钻削中的轴线偏斜问题,从加工方式、导向条布置、长孔钻削三个角度进行研究,分别介绍了三者产生影响的原因,最后通过对切削方式的合理优化,从而得出最佳的钻孔轴向直线度.     

L-Shaped Curved Hole Creation by Means of Electrical Discharge Machining and an Electrode Curved Motion Generator

The study deals with the manufacture of curved holes for water channels in moulds, which are difficult to machine. As holes are generally formed by drilling operations, curved holes are formed approximately as a combination of straight holes, which leads to interference with the smooth stream of coolant and also the low efficiency and unstable performance of cooling of the mould. To solve the problem and to create a curved hole, we devised a simple mechanism, which consists of a helical compression spring, wires, pulleys, and an electrode for electrical discharge machining, which is installed on an electrical discharge machine (EDM). The device allows the electrode to move along a curved line. From experimental results, it is found that the device enables the machining of a curved hole. In addition, the device can make an L-shaped curved hole by connecting two curved holes machined from two perpendicular directions.     

微细深孔超声轴向振动钻削装置的设计

超声振动钻削属于脉冲式的断续切削。在深孔加工方面具有普通孔加工技术无法比拟的工艺效果。文章介绍了作者基于高频振动切削原理设计的一台超声轴向振动钻削装置的结构。并将该装置用于立式加工中心上对铝、铜等材料进行了切削加工实验。实验结果表明，超声振动加工可提高微细深孔的加工精度和表面质量。这种方法特别适合于软质材料的微细深孔的精密和超精密加工。     

An investigation of the hole machining processes on woven carbon-fiber reinforced polymers (CFRPs) using abrasive waterjets

An investigation of the hole cutting and drilling processes on woven carbon-fiber reinforced polymer sheets using abrasive waterjet (AWJ) is presented. The drilling process uses a stationary AWJ to impinge a target material to make a hole, while the cutting process requires an AWJ to penetrate the workpiece before moving in a circular path to cut a hole. It is found that the holes machined by both the processes exhibit similar geometrical features, where the diameter at the top is greater than at the bottom. It is further found that the holes from the drilling process have a better roundness than those from cutting process primarily due to the jet instability during cutting movement. Plausible trends of the hole characteristics (e.g., diameter and wall inclination) and defects (e.g., delamination) with respect to the process parameters are discussed. It is shown that water pressure is the major parameter affecting hole defects. The hole drilling process yields more severe defects than the cutting process because of the initial impact of the jet. Predictive models for machined hole diameter in both processes are developed. The model predictions are in good agreement with the experimental data under the corresponding conditions.     

小孔的振动钻削与普通钻削的比较

本研究用特殊的万向联轴器作为振动源，进行了钻孔个数、加工精度、深孔加工适用性等方面的试验，获得了较好的效果，证明了这种振动钻孔方注对小孔加工的适用性．