刀具几何参数激光测量仪的开发

研制开发了基于激光传感原理的刀具几何参数测量仪,简要说明了测量系统的构成和基本原理。通过对钻头几何形状的测量实例,重点介绍了该测量仪实现三维测量的原理及特点。     

钻头测定器

在刃磨后面之后,需要确定磨削面的精度,以改进磨削工艺。同时为了稳定生产给定的钻尖形状,必须测量后面,以获得所需的磨削参数。为此,Wisconsin-Madison大学制出了一种被称为“钻头测定器”的仪器,它能自动测量钻头后面的几何形状,并在计算机的帮助下给出所需结果。本文着重介绍了该仪器的测量方法、数学模型建立、坐标测量机构。     

基于ALGORFEAS的钻头有限元模型

利用有限元软件ALGORFEAS构建出具有复杂截面几何特性的钻头三维有限元模型。与以往将钻头看作均匀等截面圆柱体而忽略了螺旋槽和头部锥面的钻头模型相比 ,该有限元模型更接近于钻头的真实形状 ,更有利于对钻削过程中钻头的动力学特性进行深入研究。     

现代滚刀测量仪器概况

滚刀的几何形状复杂，其表面是经过铲齿的非连续曲面。因此，滚刀测量属于断续表面的复合量测量。为形成复合运动，需要多坐标的展成运动。过去40多年，世界上开发了一系列滚刀测量仪。从技术上讲，滚刀测量仪历经了机械创成式到NC电子创成式、直到今天CNC齿轮测量中心的发展。在分析滚刀的几何特点及其对测量带来影响的基础上，本文较全面地论述了现代滚刀测量技术的发展和相应的产品，并介绍了我国新开发的滚刀测量仪器的工作原理及其特点。     

石油钻头的实体建模及有限元分析

石油钻头是一种形状较复杂的孔加工工具,其参数不易获取,通过光学测量技术对钻头扫描,逆向工程软件对钻头的点云数据进行处理,再利用三维软件实现三维建模;应用有限元分析软件对钻头进行有限元的数值模拟分析,可较精确地掌握钻头在工作过程中各点的受力情况,了解钻头内部应力应变的分布规律,获得应力分布图并方便地找出钻头上的危险点,为今后改进钻头的受力情况、合理设计钻头结构以及对钻头进行失效分析提供理论依据。     

智能钻头刃磨机

高性能钻头的优点是要使大多数用户很易于得到证明他们最初较高的购买成本是合算的,唯一的条件是要求钻头的再次刃磨费用比较低。钻刃的复杂几何形状需要专门的刃磨设备与方法。 常用基本方法有以下三种。 1.专用夹具 这些机械装置安装在标准的手动磨床上,利用凸轮和滑板仿形磨削钻尖的原始形状。使用这种夹具是一个缓慢的过程,并要求操作员具备熟练的     

采用光栅相位法的三维人体测量系统设计

依据相移法开发出便携式三维人体扫描仪,用于实现快速三维人体重建.阐述了光栅相位法测量三维物体的工作机理.设计出光学投影系统、相移装置及图像采集与处理模块实现人体三维测量功能.利用单片机C8051 F340搭建硬件控制平台并开发了相应的控制软件,利用VC++编制上位机程序控制三维测量系统,完成三维人体光栅图像获取及图像处理.人体模型测量实验表明:所设计的三维人体测量仪可在100ms内获取4幅变形光栅图像,经解相处理生成三维点云,通过曲面重构获取完整人体模型.测量仪具有接口方便、体积小、操作方便、测量速度快、精度高的优点,满足快速获取三维人体信息及模型重建的要求.     

逆向工程技术在石油钻采工具开发中的应用

通过对新疆某油田所使用的扩孔钻头的扫描及三维模型重构的应用实例,介绍了逆向工程在工程产品开发中的应用;论述了利用逆向工程软件Imageware对扩孔钻头的点云数据进行处理和构造曲面过程,利用三维软件UGNX进行三维造型的过程,以及利用逆向工程技术检测加工后的扩孔钻头加工精度的方法。     

PDC钻头的三维设计方法

PDC钻头在设计上的最大难度是无法精确定位，一般根据钻头冠部剖面形状的设计参数，靠经验和类比同型钻头来进行设计，设计的反复性比较大。介绍了PDC钻头的三维设计方法以及数据转换方法，从而克服了设计的复杂性，利用三维设计方法和NUMECA分析软件对PDC钻头进行设计和分析，可以大大提高钻头设计的效率。     

复杂轮廓曲面非接触三维数据测量的研究

介绍一种非接触式CCD三维数据测量仪，可对具有复杂轮廓的漫反射曲面进行测量、获取表面轮廓的三维数据，介绍了该仪器的测量原理、微机控制系统和误差分析。     

钻头形貌视觉检测及其数据融合技术

本文叙述了基于结构光法的钻头三维形貌视觉检测系统的组成和原理，重点分析了测量数据的处理方法，它们包括：原始测量数的野值剔除、形貌特征点的分离和数据分割以及基于优化理论的数据融合方法。在此 基础上，本文讨论了刃沟横截面数学模型的建立及参数的测量方法。给出了用视觉检测系统和三坐标测量机测量的刃沟横截面参数比对结果，说明本测量系统具有很高的测量精度，能够满足生产实践的需要。     

Error analysis of drill point geometry inspection using radial-view silhouette images

The conical ground drill point geometry can be described by five parameters, which are measured with the simple inspection method using radial-view silhouette images. This paper deals with error analysis of the inspection method. Different types of errors may occur while taking radial-view silhouette images of the drill point geometry. All possible setup errors have been considered and deviations from the true values of the geometrical parameters have been calculated. The sensitivities of the geometrical parameters and common angular parameters of the drill with the errors have been analyzed to develop a practical apparatus of the inspection system.     

Analysis and simulation for a parallel drill point grinder

Based on the 3-PRS parallel mechanism, a new drill point grinder is presented in this paper. The relationship between the drill point geometry parameters and the grinding kinematic parameters are described for the most commonly used conical twist drill, and the grinding kinematic equation is also derived accordingly. The virtual prototype modeling and the kinematic simulation using MSC/ADAMS are then carried out for the proposed parallel drill point grinder. The related kinematic analysis, such as the displacement and velocity analysis of the drill point and grinding wheel, the rotation angle analysis of the ball joints with respect to the initial position, etc., is obtained. From the simulation results, we can see that the proposed structure is capable of implementing the function of drill point grinding. The virtual prototype simulation can help in the parametric design and the structural design for the new grinder.     

简化钻头圆锥面刃磨法的研究

传统或简化的圆锥面钻头刃磨法被广泛地应用于钻头生产 ,通过钻头重磨与教学实验 ,在对直线钻头圆锥面刃磨法研究的基础上 ,对传统的简化圆锥面刃磨法进行数学建模 ,给出刃磨后的各项切削几何参数公式 ,并对推荐的刃磨工艺参数的可行性做了数值模拟分析。     

Practical inspection system of drill point geometry by using simple measurement jig and image processing

The proper simple inspection system for drill point geometry will support the skillful drill regrinding operation. In this paper, a newly developed system for practical use in machine shops has been described. The measurement method is based on silhouette image processing described in the author’s previous papers. But, for easy and robust inspection, a simple measurement jig was designed and the identification method of the five geometrical parameters describing its complete geometry was modified. Then, the error motion of the jig was tested and a compensation strategy of its error was proposed. The results show that the drill angles such as the outer clearance angle measured by this system are more precise than those measured by a microscope. Moreover, this system can measure the five geometrical parameters of the drill, which cannot be measured by using the microscope.     

Drill point geometry of multi-flute drills

This paper presents a comprehensive mathematical model for analysis of the geometries of conical, hyperboloidal, and ellipsoidal drills. The proposed method includes three particular features. The first is that a rotational disk-type abrasive wheel is modeled by revolution geometry, thus allowing for the normal and tangent vectors of an abrasive wheel to be obtained explicitly. Consequently, the tangent and normal vectors along the cutting edges and chisel edges of the produced drill can be obtained. The second feature is the ability of the model to determine and express drill geometries and characteristics (semi-point angle, tool cutting edge inclination, chisel angle, normal rake angle and normal clearance angle) according to all current international standards. Thirdly, the drill’s working geometries are investigated by taking the effect of feed motion into consideration. We found that cutting edge geometry can be studied without significant error even though we neglect the effect of feed. The chisel edge working geometry shows greater variation than tool geometry. Consequently, the effect of feed must be taken into consideration when studying chisel edge action during drilling operation.     

Analyses of Drill Flute and Cutting Angles

The analysis of drill cutting angles is important for the design of high-performance drill geometry. The cutting angles along the cutting edge of a drill are determined by the combination of its flute and flank surfaces. This paper examines the analysis of both flute and flank surface models and the evaluation of drill cutting angles. A new mathematical model for an arbitrary drill flute face is developed by sweeping the polynomial representation of the flute cross-sectional curve along the drill axis, with a helical movement. On the basis of the quadratic flank face, a relationship between the grinding and the geometrical design parameters of the flank face is also established. The vector analysis method is employed for the analysis of the cutting angles for various drill geometries. A comparison of the analytical results with the actual measured cutting angles of an example drill has shown that the average error is less than 5%.     

Measurement of temperature change during the implant site preparation to determine influence of tool characteristics

Implant site preparation procedure is the most important factor that affects early osseointegration performance of a dental implant. During the side preparation procedure increase in the bone temperature above critic limit causes irreversible osteonecrosis. This heat rise compromises implant area around implants thus ending with unsuccessful osseointegration outcomes.In this experimental study drill tip geometry, drill tip angle and drill sharpness affects on procedure temperature were investigated. Experiments were carried on fresh bovine bones and implant sites were prepared individually for each experimental set.     

STUDY ON THE MECHANISM OF CHATTER VIBRATION OF INITIAL PENETRATION IN DRILLING

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TC11钛合金深孔钻削工艺研究

针对钛合金材料钻削加工的难点,对TC11钛合金薄壁壳体进行了钻削加工方法的探索和研究。从刀具结构、刀片几何角度、切削参数的选择以及对工件的热处理等方面进行改进试验,优选了合理的工艺方案,解决了薄壁壳体内孔钻削加工的技术难题,提高了产品质量。