面向高速加工的复杂曲面螺旋刀路优化

针对现有螺旋切削轨迹对曲面形状适应性较差,无法直接应用于复杂曲面的局限,提出一种基于曲面重构的螺旋曲线切削法。对于复杂曲面根据各自的特点分别采用曲面提取、修补、延伸等方法重构目标曲面,以重构后的曲面作为圆柱螺旋线的投影对象获取驱动曲线,在CAM软件中以曲线驱动方式生成螺旋曲线轨迹并进行优化。VERICUT软件仿真和实际加工的结果表明:复杂曲面采用曲面重构螺旋切削法可以获得满足高速加工要求的光顺切削路径,扩展了先进螺旋切削方式的应用范围。     

用于复杂深孔内螺旋曲面加工的拉刀设计方法

对复杂深孔内螺旋曲面进行高精度和高效率加工是复杂深孔加工领域研究的热点问题之一。针对深孔内螺旋曲面加工尚需解决的关键技术建立一种通用的螺旋曲面线型数学模型,为刀具精确设计提供理论计算依据。提出了深孔内螺旋曲面拉削加工方案并进行了拉刀的三维建模,分析论述的复杂深孔内螺旋曲面拉刀设计流程和实例对于成套拉刀设计有参考指导意义。     

基于ANSYS的螺旋桩叶片仿生曲面接触有限元仿真

本文基于ANSYS对螺旋桩叶片仿生曲面与土壤的接触问题进行了有限元仿真分析.仿真分析表明,螺旋桩叶片仿生曲面的减摩效果随着仿生曲面突起宽度与突起间距的增大而增加,从而为螺旋桩叶片仿生曲面的结构设计提供了参考.     

温度对螺旋定子内腔曲面挤压成型的影响分析

对螺旋定子内腔曲面的形成原理及啮合方法进行了研究,并对国内外螺旋曲面的加工方法及应用做了一定的了解后,提出了挤压成型加工螺旋定子内腔曲面的方法。以螺旋定子为研究对象,通过建立其三维实体模型,利用有限元软件对其加工过程进行分析,得到不同温度下加工螺旋定子时所需推力,产生的内部应力及其导程的变化等重要参数,为使用挤压法制造螺旋定子提供了参考和依据。     

成型磨削砂轮廓型的设计计算

针对螺旋曲面加工过程中工件与刀具空间啮合关系的特点,主要研究螺旋曲面磨削加工过程中的刀具廓形计算。根据刀具回转曲面与工件螺旋曲面间的空间共轭关系,灵活运用啮合原理,通过数学建模、空间坐标转换等方法计算出砂轮的廓形,为后续研究提供了数学思路和理论支持。由于各类共轭曲面存在相似的共性,提出的算法对各类共轭曲面的计算与设计均有一定的帮助。     

叶片轮廓余量计算软件开发

螺旋曲面的叶片轮廓余量计算在螺旋曲面加工过程中具有重要地位.由于螺旋曲面叶片轮廓余量计算十分复杂,开发了叶片轮廓余量计算软件.     

螺旋曲面螺杆的抛光研究

介绍一种在专用数控铣床上实现对螺旋曲面进行数控抛光的加工方法，其目的是为了提高螺旋机械产品中螺旋曲面的加工精度。     

单螺杆泵的复杂螺杆转子造型及其数控加工仿真过程研究

基于CAD／CAM软件MASTERCAM．采用插值三次样条函数和利用螺旋曲面的特性进行单螺杆泵的复杂螺杆转子螺旋曲面三维几何造型，并基于仿真加工软件VERICUT，对螺旋曲面数控加工NC程序进行三维仿真。     

管状螺旋曲面的数学建模与CAD绘图

分析了常用螺旋形体造型方法的缺陷.根据圆柱螺旋面的形成原理,从研究圆形螺旋曲面数学建模入手,建立了各种截面形状的螺旋曲面造型的数学模型,并在AutoCAD中给出了基于visual-LISP的各种管状螺旋曲面的CAD绘图方法与技巧.最后,讨论了圆形截面螺旋曲面上螺旋线的形成与CAD绘图.     

回转曲面螺旋槽数控加工技术研究

为了解决回转曲面螺旋槽的加工难题,本文提出了回转曲面螺旋槽数控编程的数学模型建立方法,对其数控加工编程进行了研究,并提出了数控加工走刀步长确定的计算方法。实际加工结果表明,该方法提高了回转曲面螺旋槽加工精度和效率。     

可展面在平面上的展开及其在工程上的应用

论述了可展面在平面上展开的理论方法 ,即以可展面上一条已知曲线为基础 ,将可展面展开的方法。并以此为依据 ,探讨了工程中应用很广泛的一种可展面——渐开线螺旋面的展开问题 ,为解决工程实际问题奠定基础     

The profiling of end mill and planing tools to generate helical surfaces known by sampled points

Generation of helical surfaces with cylinder-frontal tools (end mill tool or grinding wheels) as so as with cylindrical tools (planing tools) are proceedings used in the small lot productions manufacturing or for reparations. In many situations, the surfaces to be generated are known by measuring on three-dimensional measuring machines. In this way, is possible to define a generatrix expressed by sampled points, which impose specifically algorithms for the end mill tool’s profiling. In this paper, specifically proposed are algorithms for end mill tool and planing tool profiling, designated to generate helical surfaces known in discrete form. More is assumed that the helical surface’s generatrix may be expressed only by few points, three or four, so the helical surfaces generatrix may be expressed by inferior degree Bezier polynomials using topological geometry. One of the goals of this paper is to compare the numerical results obtained by the proposed algorithm with the results obtained from profiling theoretically methods, for the same surfaces types, in order to proof the new method quality.     

变截面螺旋曲面的解析几何建模与CAD绘图

扫描变换法和路径拉伸法通常用于螺旋弹簧的近似造型,通过分析比较,指出了两种方法的不足之处.运用解析几何方法,研究了圆截面螺旋曲面的建模方法,并建立了各种截面形状的螺旋曲面通用解析表达式.同时,进一步研究了变截面螺旋曲面的形成与建模方法,并在AutoCAD中给出了基于VisualLISP的各种截面形状螺旋面的CAD绘图技巧.结果表明,此建模方法能大大提高螺旋曲面造型的精确度.     

A study on helical surface generated by the primary peripheral surfaces of ring tool

Often in the engineering practice, cutting tools bounded by primary peripheral surfaces of revolution are used because of their effectiveness. Among these, ring and tangential tools can be used for the generation of constant pitch cylindrical helical surfaces. In this paper, we present an algorithm for the profiling of these types of tools. The algorithm is based on the topological representation of the tool’s primary peripheral surface. The main goal is to devise a methodology for the profiling of tools whose surfaces are reciprocally enveloping with cylindrical helical surfaces. We present a numerical example for the numerical determination of the axial section form for this type of tools. The application method for this algorithm was developed in the CATIA graphical design environment within which the procedure is developed as a vertical application. In addition, we present a solution for the shape correction of the tool’s axial cross-section by considering the existence of singular points on the profile of the helical surface to be generated where multiple normals to the surface exist.     

3D graphical method for profiling gear hob tools

This paper approaches the issue of profiling gear hob bounded by a cylindrical helical surface with constant pitch, reciprocally enveloping with an ordered surfaces curl. The process kinematics of generation reproduces the 3D gear between the worm and the wheel. This gear has crossing axes and it is used for the profiling of the primary peripheral surface of the gear hub in the intermediary surface method (the common rack-gear of the surfaces curl to be generated and the primary peripheral surface of the gear hob). An algorithm in the CATIA design environment is presented, based onto an original method for the determination of the reference rack-gear form—the rack-gear reciprocally enveloping with the surfaces curl, using the principle of the cylindrical helical motion decomposition in translation and rotation motions. Graphical and analytical profiling examples are presented for the gear hob for generation of a parallel spline shaft and for the generation of a toothed wheel with involute teeth. Solutions for the interference problems, problems due to the singular points onto the profiles, are presented.     

An analysis for extrusion of helical shapes from round billets

A method of analysis is proposed for three-dimensional extrusion of a helical shape from a round billet. It is reported that a helical shape can be made by hot extrusion through a square die. In this paper, it is suggested that a helical shape be effectively cold extruded through a continuous die with appropriate lubrication. The extrusion of helical shapes can find practical application in some useful products. However, the analytical method regarding this kind of extrusion has not been attempted so far.A kinematically admissible velocity field is derived for the extrusion model where a round billet is extruded into a twisted helical section with a long elliptic cross section. The axis of the cross section is rotating during extrusion. By assuming proper stream surfaces, the velocity field is obtained by deriving the equation of a stream line. Then, an upperbound solution is formulated for the rigid-perfectly plastic material. Computation for the upperbound pressure is carried out for various process variables such as reduction of area, friction, rotation of axis, aspect ratio of a product, die length and overall die profiles.     

Mathematical model of a helical gear with asymmetric involute teeth and its analysis

This paper describes a simple approach based on the gear theory for deriving a helical gear with asymmetric involute teeth. A helical gear with asymmetric involute teeth can be easily obtained through the envelope theory for the one-parameter family of surfaces. The mathematical models for asymmetric helical gears can be provided by the application of two imaginary rack cutters. The investigation on the undercutting analysis of the asymmetric helical gear is studied based on the developed mathematical model and the method of tooth-profile shifting. Here we provide geometric modeling of the designed asymmetric helical gear meshing when assembly errors are present. Stress analysis for the helical and the cylindrical forms are constructed. To illustrate the effectiveness of the approach, an analytical expression of helical gear with asymmetric involute teeth is given.     

Mathematical model of a helical gear with asymmetric involute teeth and its analysis

This paper describes a simple approach based on the gear theory for deriving a helical gear with asymmetric involute teeth. A helical gear with asymmetric involute teeth can be easily obtained through the envelope theory for the one-parameter family of surfaces. The mathematical models for asymmetric helical gears can be provided by the application of two imaginary rack cutters. The investigation on the undercutting analysis of the asymmetric helical gear is studied based on the developed mathematical model and the method of tooth-profile shifting. Here we provide geometric modeling of the designed asymmetric helical gear meshing when assembly errors are present. Stress analysis for the helical and the cylindrical forms are constructed. To illustrate the effectiveness of the approach, an analytical expression of helical gear with asymmetric involute teeth is given.     

工况参数对船用斜齿轮动态性能的影响

以某型船用单级斜齿轮传动为研究对象,针对其工况复杂多变的特点,基于Abaqus/Explicit显式动态分析方法,建立了斜齿轮副有限元模型.对额定工况下齿根动应力进行了仿真,重点讨论了负载扭矩和主动轮转速等工况参数对齿根最大动应力的影响.结果表明：斜齿轮齿根最大动应力随着扭矩和转速的增大而接近线性增加,且不同齿面的齿根动应力的增加速率不同.研究结果对船用斜齿轮副的优化设计具有一定参考价值.