碟型砂轮钻头刃磨机原理设计--直线主刃刃磨

本文在直线主刃圆锥面刃磨原理的基础上，分析了固定圆锥角实现各种结构参数钻头刃磨的可行性，分析了碟型砂轮内锥面刃磨的干涉条件，给出了碟型砂轮刃磨机的设计方法，同时给出了一个设计实例。通过实例明确了碟型砂轮刃磨机的局限性。     

双曲面麻花钻数学模型及刃磨方法研究

提出了具有非直线刃的回转双曲面麻花钻数学模型的简化计算方法及钻头锋角合理定义点的选取,给出了双曲面钻型刃磨时其设计参数与刃磨参数的相互关系,并对此类二次回转曲面钻头提出了与传统的刃磨方法有根本区别的分层磨削插补成形的点磨削成形刃磨新方法。对以二次回转曲面作后刀面的钻头进行了刃磨原理分析。     

麻花钻锥面磨削装置

本装置采用圆锥表面磨法对钻头进行后面刃磨,可保证磨出的钻头具有合理的后角,对称精度高。     

钻头刃磨新方法的开发实验

西德DIN(国家工业标准)中有缩短钻头横刃的规定(如图1)。但是,该规定尚不充分,专家们仍注意研竟钻头刃磨方法对于孔加工精度等的影响,西德GUHRING公司最近针对钻头的刃磨方法又进行了各种研究,取得了新成果。带有螺旋刃棱及复数切削面的群钻等刃磨方法,使钻孔的定心性及切削能性大大提高,被称之为钻头刃磨的最优方案。但是,在实验中证明这些新的钻头刃磨法无论哪一种,决不是较通用的方法。然而传统的普通钻头的圆锥型刃磨法却适用于多种加工。     

一种改进标准麻花钻头主后角的新方法

麻花钻头的主后角是后刀面切线与切削平面之间的夹角,是以钻轴为轴心线的圆柱截面内测量的,通常是指主切削刃外缘处的圆周后角。主后角是刃磨钻头时最重要的切削参数,也是整个钻头中主要的几何角度,它在钻孔加工中起着重要作用。一、标准麻花钻头的主后角有待改进在各机械工厂的切削加工中,标准麻花钻头的主后角除少数采用机械刃磨外,绝大多数均由熟练工人手工刃磨,一直以普通的锥面刃磨(即圆锥面的刃磨法)为主。刃磨     

麻花钻锥面磨削装置

本装置采用圆锥表面磨法对钻头进行后面刃磨，可保证磨出的钻头具有合理的后角，对称精度高。     

虚轴钻头刃磨机运动方程的研究

用矢量表示了虚轴钻头刃磨机的基本结构,根据圆锥面钻尖的磨削参数,采用矢量变换推导了在虚轴机床上刃磨圆锥面钻尖的运动方向,进而求出杆长矢量,作为机床运动控制的依据。     

基于UG的标准直柄麻花钻三维实体建模

利用麻花钻直线刃圆锥面刃磨法的数学模型,介绍了在UG环境下,根据标准直柄麻花钻的相关几何参数和制造参数,探讨和研究了利用此种刃磨法的数学模型,进行麻花钻三维实体建模的详细方法。     

锥面刃磨可展直纹面与后刀面刃磨

对锥面曲面刃磨问题进行了研究 ,建立了统一的数学模型。计算了椭圆锥面后刀面刃磨钻尖的结构参数 ,分析了锥面机构参数以及刃磨参数对钻尖结构参数的影响。并且对椭圆锥面刃磨与圆锥面刃磨进行了比较。     

新型麻花钻圆锥面后刀面刃磨参数的近似求解

根据一种新型麻花钻的结构特点,建立其圆锥面后刀面的数学模型,并推导了近似求解圆锥面后刀面刃磨参数的方程组。根据刃磨参数的求解结果,在UG中建立了麻花钻的三维参数化实体模型,并对各设计参数进行检测。其结果表明:在公差范围内检测值与理论设计值完全一致,从而证明了这种近似解法能够满足工程需要。     

非共轴螺旋后刀面微钻的五轴联动刃磨方法及其钻削性能研究

微细钻头的几何结构是影响刀具钻削性能和微孔加工质量的关键因素。非共轴螺旋面钻尖由连续的螺旋后刀面组成,相比平面钻尖能有效的提高刀具的刃磨效率及其钻削性能。针对非共轴螺旋面钻尖,推导后刀面形成过程中螺旋运动发生线的位置方程,建立了基于砂轮和钻头接触线的后刀面数学模型。根据六轴数控工具磨床的运动原理,提出非共轴螺旋后刀面五轴联动刃磨方法。分析砂轮与螺旋槽之间的相对运动关系,提出微细钻头螺旋槽的数控加工方法。进行非共轴螺旋后刀面微钻的刃磨试验,验证了该刃磨方法的可行性。进而采用制备出的具有相同几何结构参数的平面、锥面和非共轴螺旋面微细钻头进行不锈钢钻削试验,结果表明非共轴螺旋面和锥面微钻的钻削力、后刀面磨损明显小于平面微钻,并且非共轴螺旋后刀面微钻的横刃磨损程度小于平面和锥面微钻。研究证实了所提出的五轴联动刃磨方法可以有效地制备出较高钻削性能的非共轴螺旋后刀面微细钻头。     

曲线刃麻花钻数学模型的研究

通过对圆锥面后刀面曲线刃麻花钻的结构进行分析,建立了其容屑槽、圆锥面后刀面、内刃前刀面和切削刃的数学模型,为刃磨参数的求解和三维参数化实体模型的建立提供了必要的理论基础。     

基于Hopkinson压杆试验的小钎杆动态应力特性研究

在对锥体连接钎杆和整体钎杆2种典型小钎杆的应力传播模型进行理论分析的基础上,通过Hopkinson压杆试验系统对这2种钎杆杆体中部和钎头端部进行了动态应力测试。测试结果表明:2种钎杆杆体中部应力幅值基本没有差异,但锥体连接钎杆接头处具有30%的应力波反射,而整体钎杆没有;整体钎杆钎头端部最大入射应力波幅值的平均值比锥体连接钎杆的相应均值高出23%,使得整体钎杆的凿速比锥体连接钎杆的要高,但其损坏更快,预期寿命只有锥体连接钎杆寿命的18%,故整体钎杆更适用于软岩钻孔作业,而锥体连接钎杆更适用于硬岩钻孔作业,该试验研究为技术人员如何选用钎杆提供了理论指导。     

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.     

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.     

任意形状钻头切削刃的受力预测模型

建立了钻头切削刃的数学模型，并通过钻头切削上任意微元的几何关系，运动关系、受力关系及切削原理，建立了钻头任意形状切削刃的受力预测模型，同时推导出了其具体表达式，由第一只钻头的实验结果，确定了模型中的相关系数，并用第二只不同形状的钻头实验和预测进行了验证，证明了模型的准确性，为钻头寿命的预测模型提供了力的模型，同时也为同行学者提供了该论著的研究方法。     

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.     

Modeling,simulation and manufacturing of drill flutes

The designing of twist drill flutes (as well as that of end mills and of some combined tools) cannot be separated from the way they are manufactured. The aim of this paper is to present an intuitive direct method for modelling, simulation and manufacturing of the drill flutes with different shapes using conical grinding wheels with standardized shapes. The mathematical approach is described, which enables us to determine the flute profile in a section perpendicular to its axis as well as the manufacturing parameters. The grinding wheel has an initial position with respect to the cylindrical work piece, which is described using four parameters (Denavit Hartenberg parameters). We have presented algorithms in pseudocode that produce the flute shape and that compute the optimum parameters of the wheel position in the manufacturing process. Subsequently, a software application based on the aforementioned model is able to create visualizations of the flute shape. The analysis of the flute shape has enabled us to understand the influence of the geometrical parameters and the position of the grinding wheel on the resulting product in the grinding process. The order in which these parameters are to be set is also specified. We have built atlases of maps presenting the influence of the geometrical parameters and the position of the grinding wheel in the grinding process upon the shape of the flute. The validity of the method is proven by the agreement of the computed values with the input and output data produced by experiment. The proposed method allows helical flutes to be generated solely by using cylindrical and conical grinding wheels of standard shapes.