对摇臂钻床传动设计的讨论

大家都知道,在摇臂钻床上,可以迸行钻孔、扩孔、锪孔铰孔、镗孔、攻螺纹、用刀头和端面刀具切削平面和做其它类似的加工工序。利用特种刀具还可以做孔内车削环形沟槽等复杂的加工工序。通常,在摇臂钻床上加工的工件都是中等件和大件,被加工孔的直径和被加工工件的材料都在一定的范围内变化。因此,摇臂钻床的主轴转速必须具有较大的调整范围。表1是各种规格摇臂钻床的常用的调整范围。规格愈大的摇臂钻床,其调速范围愈大。 为不使生产率损失过大;主轴转速数列的公比φ 常取为 1.26,也有取为 1.41的。这样一来,主轴转速级数就较大,给传动设计…     

大螺距交叉油槽的加工及工装设计

1．加工难点 普通螺纹的加工方法有多种,其中以钻床攻螺纹、板牙套螺纹、车床车螺纹、铣床铣螺纹以及螺纹滚轧最为普遍。但带大螺距油槽的套筒却超出了普通螺纹的加工范围,如图1所示。其中外圆、内孔以及工件正中间的内孔油槽的加工都较容易解决,关键是客户用文字特别注明的贯通两个端面的“∞”形油槽成为这个产品加工的难点。     

模具调试中的孔位转移

在模具的生产和调试过程中 ,经常要对某局部图　 11 新镶块　 2 模具位置进行更换 ,往往更换后的镶块上所加工的连接孔要与模具上螺纹孔的位置相对应才能保证镶块装配的位置度。如图 1所示 ,新镶块 1要求在上面加工通孔与模具2上的旧螺纹孔(箭头所指 )连接。钳工一般的操作方法是用测量和划线找出镶块上的钻孔位置 ,其实可图　 2直接在摇臂钻床上实现模具的螺纹孔向镶块的位置投影。现将具体的操作方法介绍给大家。如图 2所示 ,将模具固定在钻床的工作台上后 ,在主轴上装上与螺纹孔相同大小的丝锥 ,旋转主轴将丝锥攻入螺纹孔并锁紧钻床 ,这…     

摇臂丝杠孔端面的加工

摇臂(28011C)是Z30_(32)~(25)×10摇臂钻床上的主要零件。该件上有一φ95H7丝杠孔,孔的端上锪平φ128mm端面,孔与端面的垂直度公差为0.02mm,φ95H7的端面加工很不稳定,80％左右达不到设计要求,检查结果垂直度公差都在0.04～0.06mm之间。由于工件的这项要求不合格,直接影响摇臂升降时噪声大,摇臂升降时产生颤抖,从而影响了原设计的机械性能,对该产品创部优质产品直接受到影响。     

PLC在全自动专用钻床控制系统中的应用

钻床是一种用途广泛的孔加工机床,主要用于钻削φ80mm以下的孔,此外,还可以进行扩孔、铰孔、锪孔、攻螺纹和锪端面等工作,而专用钻床是钻床中的一种,它主要用于大批量生产某一特定零件。现有如图1所示的工件,需要大批量生产,其中一道工序是钻削工件上一个φ30mm的通孔,工件材料为铸铁,为此,设计一台全自动专用钻床,     

盾构机主驱动连接环油脂孔端面O型密封环槽加工方法改进

介绍了盾构机主驱动连接环油脂孔端面O型密封环槽加工工艺的改进,制作了一种切槽刀,实现了利用摇臂钻床代替数控钻床铣削的加工,并且解决了数控钻床受尺寸限制,无法加工大尺寸零件的问题。     

一种可旋转的钻模夹具

多缸机机体两侧面孔系比较多,孔的位置比较复杂,由于生产批量限制及孔的位置复杂,一般生产都不是由专机来加工,而是在摇臂钻床上加工的,加工这两侧面孔需要多台摇臂钻床和多道工序来完成。就我公司生产的 N485机体为例,在图 1中,该面有四个闷头孔,多个螺纹孔底孔、油孔、斜油道螺纹孔底孔和油标尺螺蚊孔底孔等,加工这些孔时,可以分三道工序：加工 5个斜油道螺孔孔底纹为一道工序;加工油标尺螺纹孔底孔为一道工序;其余孔由于在一个平面上,可以合为一道工序多工步来完成。在图 2中,该面有三个闷头孔,多个螺纹孔和一个斜油道螺…     

大型经济型数控钻床结构设计与研究

正摇臂钻床作为孔加工机床主导产品已经有几十年了,多年来一直处于销售的旺盛期,但是随着自动化技术的发展,特别是数控技术在机床上的发展,摇臂钻床的低生产率、低精度、低柔性的缺点日益突出。据调查研究,目前市场上越来越多的管板类零件尺寸都达到3~4m甚至更大,这么大尺寸的零件上往往需要加工上千个孔,而且孔的尺寸大小不同,有的孔还需要攻螺纹,如果用要在普通钻床加     

薄板螺纹孔攻丝

在冲压件生产过程中,经常遇到薄板螺纹孔的加工问题,采用普通丝锥在摇臂钻床上攻丝,制出的螺纹合格率仅达30％～50％,严重影响产品质量。 为此,我们制作了攻丝辅具(附图)。在螺纹孔部位上加工出比螺纹公称尺寸大1～2mm的过孔,并在适当部位设置夹紧装置,使零件与辅具组成一个刚性体,有效地提高了系统的刚性。     

卧式车床改半自动卧式钻孔机

我单位在加工如下产品时（见图1）遇到钻孔的难题,工件中心Ф33mm孔,直径较大而且比较长。如果在车床上采用普通的钻孔方法进行加工,既费时又费力。若采用摇臂钻床加工,由于工件较长,受行程限制,操作不方便。若采用专用钻孔机,设备成本大,加之生产能力有限。为此,我们对车床进行了改造,较好地解决了这一问题。效率比卧式车床提高2～3倍以上,质量也有较大提高。     

万吨桨油孔和起吊孔的加工

在分析了万吨桨起吊孔和油孔的加工特点后,给出了使用小万向钻和特殊钻头以及间歇进给和退出的办法进行万吨桨油孔的深孔加工;使用小万向钻和专用工装采用先钻后镗,分层切削,逐渐去除余量,扩大孔径直到设计尺寸.经过实际生产的检验,所设计的方案取得良好的效果,可以满足万吨桨加工需要.     

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.     

多孔单工位组合钻床主轴箱传动系统设计

从企业实际需求出发,在全面分析被加工零件的基础上,指出现有设备的不足,不仅工人劳动强度大,而且生产效率低,不利于保证零件加工精度,采用16孔单工位组合钻床主轴箱的创新设计可解决上述问题。     

基于UG二次开发的深孔钻参数化设计

为优化BTA深孔钻,提高刀具设计效率,对BTA深孔钻进行了参数化设计,采用UG/Open软件建立了考虑机床、刀具、加工工艺等多种因素限制为约束条件的深孔钻结构参数,实现了基于UG二次开发的深孔钻参数化设计,并按照模型进行刀具试制,验证了参数化模型的有效性。     

Kinematic modeling and parameter identification of a new circumferential drilling machine for aircraft assembly

Automated fastener hole drilling is a key technology for low-cost and high-quality assembly of aircrafts. In this paper, a new circumferential drilling machine for fuselage assembly of large aircrafts is introduced. In order to meet the required position accuracy of drilled holes, this paper focuses on the kinematic calibration of the machine in order to improve its positioning accuracy. A modeling strategy, which combines the Denavit-Hartenberg (D-H) method and a modified version of the Hayati-Mirmirani (H-M) method, is proposed to deal with the special kinematic structure of the arc-base drilling unit of the machine. Main issues in kinematic parameter identification such as definition of objective function, calibration data selection, acquisition of initial values, and setting of convergence criteria are also discussed. Experiments of repeatability testing and kinematic calibration have been performed, and the results show that the positioning accuracy of the arc-base drilling unit is comparable to its repeatability after calibration. This suggests that the proposed kinematic calibration method is effective. Actual drilling tests have been performed on a simulated aircraft fuselage after implementing the identified kinematic model in the machine’s control software. Position errors of drilled holes are within ±0.5 mm, which meets the requirement for fastener hole drilling in the fuselage assembly of large aircrafts.     

State-Of-Art,Challenges, and Outlook on Manufacturing of Cooling Holes for Turbine Blades

A cooling hole is important structure of turbine blades for high-performance aircraft engines. It is very challenging to manufacture cooling holes in superalloys including nickel-based and titanium alloys. This article aims to provide a critical assessment on the major types of machining processes for manufacturing cooling holes. The process mechanism, efficiency, form accuracy, and surface integrity of the state-of-art of four machining processes, i.e., mechanical drilling (MD), electrical discharge drilling (EDD), laser drilling (LD), and electrochemical drilling (ECD) have been thoroughly analyzed and compared in details. The future challenges and future potential research directions for the machining processes are also discussed.     

一种安全快速的机动攻丝夹具的设计与应用

分析了现有的攻丝夹具在进行小直径通孔或盲孔攻丝时存在的弊端或不足,并提出了相应的解决方案。开发了一种能够在台钻、摇臂钻床、钻铣床和车床上使用的安全快速的机动攻丝夹具,并介绍了其结构组成、工作原理和特点。     

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.     

三菱FX2N系列PLC对摇臂钻床电控系统的改造

利用三菱微型FX系列可编程控制器(PLC),结合电气控制技术,实现了对Z3040摇臂钻床控制系统的改进。分析了系统的硬件及软件设计,提供了主要的硬件原理图和软件梯形图。实践结果证明,改进后的Z3040摇臂钻床控制系统功能先进,实用,可靠。     

Predicting radial overcut in deep holes drilled by shaped tube electrochemical machining

Shaped tube electrolytic machining (STEM) is a versatile and relatively low cost process for drilling deep, high aspect ratio holes. Since the radius of a drilled hole is the sum of the tool radius and radial overcut, one crucial aspect of dimensional accuracy is radial overcut. However, models of overcut in the literature are scarce and have primarily been restricted to shallow holes. Moreover these models were purely empirical and therefore restricted in scope. A fundamental mathematical model that uses STEM operating parameters (voltage, tool diameter and feed rate, bare tip length and electrolyte composition) as inputs to predict radial overcut has been developed. Predictions from the proposed radial overcut model are much closer to experimental data compared to those from the models available in the literature. A novel contribution of this study has been the formulation of a methodology to determine the magnitude of current flowing out radially from the bare tip length using experimentally measured total current values.