等螺旋角圆锥型模具立铣刀齿槽刃磨法——非圆齿轮传动法

为保证刀具最佳切削性能,圆锥(或笔状)型硬质合金模具立铣刀的螺旋槽,是按等螺旋角设计的,即要求圆锥型面刀刃上各点的螺旋角相等,使刀刃上各点的前角相等。本文从圆锥形立铣刀的等螺旋槽的形成原理、数学模型的建立和加工原理,论述了加工该刀具的等螺旋槽刃磨床的传动原理及实现磨床运动的方法之一——非圆柱齿轮法。并论述了非圆柱齿轮的设计原理,为非圆柱齿轮法加工等螺旋角圆锥型模具立铣刀齿槽刃磨床设计,提供了可靠的理论。     

螺旋凸凹模的铣削

螺旋凸凹模分为凸模和凹模,属容积式模具,要求有一定的配合间隙和接触面积,在铣床上铣削螺旋槽时,铣出的螺旋槽不论是槽口上的螺旋线还是槽底上的螺旋线,其导程是相等的。因为当工件转一周时,铣刀相对于工件在轴线方向上移动的距离等于导程,但是由螺旋角的计算公式tanβ=πD/P_z可知,在一条螺旋槽上,自槽口到槽底,不同直径处的螺旋角是随着工件直径D的变化而变化的,由于螺旋角β的大小不同,同一截面上切线的方向也不同,加工时往往产生干涉现象,即在铣削过程中刀具把螺旋槽的下部多切去一部分,使槽的截面形状产生偏差,使铣出的螺旋槽出现上窄下     

基于SolidWorks的刀具螺旋槽的模拟加工分析

1.刀具螺旋槽的加工形成机理 金属切削刀具产品中,带有螺旋槽的刀具很普遍。如：麻花钻头、螺旋槽立铣刀、螺旋槽丝锥、可转位螺旋立铣刀等,刀具螺旋槽除热轧及扭制等无屑加工形成以外,绝大多数情况下是靠铣削形成的。如图1所示,β为螺旋角,λ为螺旋升角,D为工件直径,L为导程,L=πD/tanβ。     

大螺旋升角螺旋槽的数控车削

正近期,我公司加工了一批零件,其外圆表面带有大螺距螺旋槽,且螺旋槽截面形状为带R0.5 mm圆弧角的直角三角形,加工难度较大。在接到试制图样并初步分析后,我们首先想到的是用四轴加工中心和成形铣刀铣削该大升角螺旋槽,这种工艺方案需要定制或自制带圆弧角的90°成形铣刀,再利用四轴机床的A、X两轴联动来加工大升角螺旋槽。由于试制进度较紧,考虑到生产效率和后期批量生产的因素,我们否定了原四轴铣加工方案,最终确定采用数控车床车削工艺来加工该槽以提高生产效率。1.零件分析如图1所示,零件外圆为25 mm,螺距P=40 mm,螺旋槽形状为90°三角形,圆弧角为     

螺旋槽丝锥的改进设计与加工方法

为了改进切削不同材料时的丝锥结构,提出了由四段相切圆弧构成的丝锥螺旋槽,切削圆弧的偏移控制丝锥的切削前角,卷屑圆弧控制切屑的卷屑与断屑,容屑圆弧控制容屑空间的大小,刃背圆弧控制丝锥刃背后角的大小,丝锥螺旋槽数、前角、后角、芯径和刃带可根据不同的被加工材料选取。此槽形容屑空间大,尤其适合轻合金材料的加工,槽与背可一次成形加工。加工螺旋槽时,由于螺旋槽导程以丝锥最大外圆尺寸计算,会产生干涉现象,因此根据丝锥螺旋槽曲线应用神经网络与数据建模方法,拟合出丝锥槽铣刀刃形曲线及砂轮刃形曲线,以此曲线制作出螺旋槽铣刀和螺旋槽砂轮刃形,可精确铣削和磨削丝锥螺旋槽形。     

等螺旋角圆锥形刀具螺旋槽的铣削工装设计原理

等螺旋角圆锥形螺旋齿刀具 (如圆锥形立铣刀、锥度螺旋齿铰刀等 )由于刀齿刃口上每一点的螺旋角相等 ,使刀具的实际前角增大 ,因此具有切削平稳轻快、加工表面质量好、刀具寿命长等优点 ,特别适用于模具加工。本文介绍一种可安装在Ｘ62Ｗ铣床上 ,通过改变工件回转角铣削等螺旋角圆锥形刀具螺旋槽的工装设计原理。该工装结构简单 ,装卸、调试方便。　　1　等螺旋角圆锥螺旋线方程如图 1所示 ,设等螺旋角圆锥螺旋线所在圆锥体的锥顶半角为α ,直角坐标系ｏ ｘｙｚ的原点ｏ定于锥顶 ,ｘ轴与圆锥体的轴线重合 ,上述螺旋线的方程为图 1ｘ =ｅθｔ…     

渐开线等螺旋角指形铣刀

本文介绍了等螺旋角指形铣刀的设计特点、使用条件及切齿实例,并以加工模数22mm的齿轮为例,对直槽指形铣刀和等螺旋角指形铣刀的切削效果进行了比较。从切削比较中得出,采用等螺旋角指形铣刀加工大模数齿轮比用直槽指形铣刀优越。     

螺旋密封性能的试验研究

螺旋密封是一种非接触式节能密封。采用自主设计加工的试验装置,对螺旋密封的螺旋升角、螺旋槽宽等不同的螺旋结构参数做了对比研究。通过试验分析得出各螺旋参数对螺旋密封性能的影响情况:螺旋升角在15.4°时密封性能较好;螺旋槽宽度在12mm时密封性能较好,槽宽在8mm和4mm时密封性能都较差;齿顶间隙增大为0.3mm,螺旋密封的密封能力大大降低。     

异型螺旋曲面数控加工运动学研究与应用

通过对加工运动学原理的研究,找出曲面上的曲线也存在着活动的特征标架这一特性,提出了模仿特征标架沿曲面曲线运动的特征加工法。并以碟形砂轮加工等螺旋角锥形铣刀刀槽作为加工异型螺旋曲面的实例,对特征加工法的应用予以说明。     

铣螺旋沟槽用单角铣刀的角度计算

<正> 加工螺旋沟槽应设计专用成型铣刀。根据刀具的槽型尺寸、齿数、螺旋角等参数,通过计算给定成型铣刀的型面,用来制造专用铣刀。但实际生产中对于小批量甚至单件生产的各种专用螺旋铣刀的沟槽铣削,不可能也没有必要制造各种各样的成型铣刀库存备用。多年来我们一直使用单角铣刀铣螺旋沟槽。实践证明采用单角铣刀代替成型铣刀加工螺旋沟槽是适用的。但是我们在生产中使用的图纸,大部分给出的槽型角不正确或没有给出槽型角。工人在加工时选择铣槽用     

Discussion on the problems related to NC machining of toroid-shaped taper cutter with constant angle between cutting edge and the cutter axis

Defining the helical angle as the angle between the cutting edge and revolving axis of the cutter presents the designing models of the cutting edge and helical groove of a toroid shaped taper cutter. Under the condition of a certain revolving speed, the relative radial and axial feeding speeds of the grinding wheel in two-axis NC machining of the cutter are deduced. The models for calculating the actual obtained groove and the simulation-method of computer are also provided.The surface near to the top of the end cutter has no helical cutting edges and infinite feeding speeds of NC machine. It is necessary to adopt a supplementary cutting edge. A supplementary cutting edge is designed as a cutting edge with a constant pitch. This paper provides valuable reference for the design and NC machining of this kind of toroid shaped taper cutter.     

A manufacturing model of helical groove on rotary burr and a universal post processing method

A systematic machining theory and precision method to determine cutter location in a grinding system is presented for rotary burr. First, the helical cutting edge on various kinds of revolving surfaces is built. Then, based on the geometry model of the helical cutting edge, the smooth spiral rake surface with constant normal rake angle and flank surface can been formed during the one-pass grinding process by this method. No interference between the grinding wheel and workpiece happens by the wheel special rotation. The method has the characteristic of detaching the grinding wheel path solution from specified machining conditions. The grinding wheel path is suitable for different NC machine tools through post processing. Meanwhile, a mechanism kinematic model of the NC machine tool is built, and a generalized algorithm for post-processing of multi-axis NC machine tools is presented. This model is applied to arbitrary configuration of NC machine tool, and the motion value for each axis will be generated by the inputting structure and motion parameters of the machine tool. The model, together with the machining method mentioned in this paper, make the calculation and generation of the grinding wheel path simpler and universal. At last, the validity of the method given in the paper is identified by an example of grinding.     

<Emphasis Type="Bold">CNC Rake Grinding for a Taper Ball-End Mill with a Torus-Shaped Grinding Wheel</Emphasis>

A new grinding method using a torus-shaped grinding wheel and a machining path generation method with a novel moving coordinate system are proposed. With this new grinding method, the smooth spiral rake surface of a taper ball-end mill with constant helical angle and constant normal rake angle can be formed during one grinding process and the normal rake angle can be obtained accurately. The novel moving coordinate system is established based on taking account of both the cutting edge curve and the cutter body surface. By means of the novel moving coordinate system, the machining path generation becomes very simple. The proposed grinding method and the machining path generation method are verified by 3D simulation results.     

特种回转面刀具螺旋槽的通用几何模型

针对数控磨削螺旋槽的特点 ,提出了基于一般特种回转面刀具刀刃曲线和刀面截形的螺旋槽通用几何模型。该模型采用统一的形式表示螺旋槽 ,为特种回转面刀具的设计和数控加工提供了理论基础。该模型也适用于其它类型的回转刀具     

基于UG的螺旋叶片数控五轴加工

为提高螺旋叶片的加工效率和质量,提出了一种新的综合优化方法.以螺旋叶片高效率、高质量、无干涉五轴加工刀具轨迹为目标,采用UG CAM可变轴曲面轮廓铣的曲面区域驱动方法,选择合适的投影矢量方向和刀轴方向,采用合理的加工工艺、切削用量和优化进退刀,采用自定义的后处理文件生成了相应数控系统的数控代码实验结果表明该零件的加工质...     

A Precision Tool Model for Concave Cone-End Milling Cutters

The paper presents a comprehensive manufacturing model that can be used to produce a concave cone-end milling (CCEM) cutter on a two-axis NC machine. A CCEM cutter possesses many distinct features that are superior in many cases to the traditional flat-end milling cutter for producing parts with multiple sculptured surfaces. Based upon the given design parameters and criteria, the equation of the helical flute groove and the curve of the cutting edge at the end of the helical flute are derived and presented. By using an inverse problem-solving technique, the sectional profile of the grinding wheel, the tool compensation for machining, and the feedrate of both NC axes are consequently obtained. The design results are compared with the measured data obtained from the NC produced CCEM cutter. The satisfactory comparative verification indicates that the tool design and manufacturing model presented in this paper is theoretically sound and it can be automated easily. The proposed method is widely applicable for the mass production of various high-efficiency milling cutters.     

Study on Rotating Cutters with Different Definitions of Helical Angle

This paper presents the similarities and differences of the design models of the cutting edge and flute section corresponding to the different definitions of the helical angle. The correlative models and simulation results for the cutting edge are presented. The section profile and relative feeding velocities of the grinding wheel in the NC machining of the cutter are deduced. The effects of design and manufacture of the cutter are analysed according to a computer simulation of the flute surface enveloped by the grinding wheel. In addition, the deviation of cutting edge, residual material and lack of land caused by the modified radial feeding velocity are taken into consideration. In order to finish the residual material and rebuild the land of the cutter, a post-process method has been developed in this work. Based on the differences of the results, a rotating cutter that has a constant angle between the cutting edge and generatrix curve has many advantages in its design and for NC grinding. Therefore, it is suggested that the helical angle defined as the angle between the cutting edge and the generatrix curve is a better choice when designing a rotating cutter.     

一种隐函数NC刀具轨迹的绘制方法

一般的数控编程软件,都是基于参数曲面的,但参数函数表达式在许多方面不如隐函数表达式.把隐函数的优势应用到数控加工编程中,即对于截面法的数控加工,求出刀具切削平面与隐函数曲面的加工轨迹,再用正负法绘制刀具轨迹曲线.首先对单调NC轨迹曲线进行绘制,进一步用不求极值点坐标而实现自动控制变向的方法,求出NC加工轨迹;该方法简单、快速,能够实现隐函数曲面的数控加工编程,具有很好的实际应用价值.     

虚拟加工系统研制与加工误差分析

面向数控车削加工过程研制了一个虚拟数控加工系统。该系统以Windows2000为开发平台，以Visual C 6．0为开发工具，基于OpenGL技术实现了数控车削加工过程3维仿真。该系统能够有效地仿真数控车削过程，具有更接近实际车削加工过程的特点。同时在仿真研究中，分析了加工过程中由切削力导致的加工误差，实现了对虚拟车削工件加工误差的预测。     

斜圆柱结构的新型微细球端铣刀的设计与制造

针对微细切削刀具的特点与应用需求,设计一种斜圆柱结构的新型微细球端铣刀,将铣刀球端刀刃复杂的空间曲线转化为易加工的平面曲线。根据所设计铣刀的几何结构特征,从制造工艺方面进行刀具结构的调整,分析刀具的刃磨成形原理,并在微细刀具数控刃磨机上完成该刀具的制作。通过与传统螺旋槽球端铣刀和椭圆柱刃型球端铣刀的切削性能对比试验,研究所设计刀具的切削性能。试验结果表明,所设计的微细球端立铣刀在显著降低刀具制备难度的同时,具有较高的切削刃强度,能够满足硬脆性材料的微细切削要求。