CAXA制造工程师典型五轴零件加工工艺研究

以数控竞赛样题为例,分析了零件结构,制定了加工工艺,采用CAXA制造工程师软件编制数控加工程序,重点阐明了3+2定向加工加工编程要点,以及基于Module Works组件的部分五轴加工策略的使用方法.最后通过Vericut软件仿真,验证了CAXA制造工程师软件的编程高效性及可靠性.     

General tool correction for five-axis milling

In this paper a method is presented by which cutter location data can be determined for any type of milling tools defined according to DIN 66215 whereby any point of the tool can be defined as the contact point. In addition, the cutter location point for 5-axis milling can be determined using a single formula for any type of milling tool.     

数控铣床与加工中心夹具设计

提出针对数控铣床、加工中心所用夹具的设计方法.合理的夹具设计能充分发挥数控机床的潜力,提高加工效率.提供加工中心夹具设计实例.     

面向五轴数控机床的可视化方案设计

五轴数控机床是1种具有战略地位的加工设备,其功能和成本很大程度上决定于机床的方案设计.采用可视化设计的方法对五轴机床实施方案设计.在简要介绍方案设计和可视化设计概念的基础上,详细叙述了基于ADAMS的可视化方案设计流程,包括机床运动方案及结构布局的初步确定、针对各方案进行运动模拟和对选定的方案进一步参数化仿真等内容.最后,以开发某五轴加工中心为例,按照所提流程进行了可视化方案设计研究,提出了龙门式、立式等3种运动方案和布局,并在运动仿真及优缺点对比分析的基础上,选定龙门式结构为最终的设计方案.     

Design for automating the inspection of manufacturing parts

The integration of quality into management of advanced manufacturing systems has not typically included automated approaches. With the advent of automated inspection and quality tools such as coordinate measuring machines and other dimensional measuring equipment, the linkage with integrated manufacturing systems seems natural. This paper shows the functional relationship of computer aided process planning to automated inspection process planning. The series of functional activities within each of these frameworks are mapped in this paper. The operational environment to include computer aided quality control in an integrated manufacturing system is also defined.     

A study on the five-axis end milling for sculptured surfaces

The direction vector of milling cutter for CL-data of five-axis milling is obtained by the fact that the bottom part of the milling cutter rides on free-form surfaces using the z-map method. Since the direction vector is known, CL-data can be transformed to the NC-code with regard to the geometry of the five-axis machine and post-processing. For uniform surfaces, the tool path is created from the prediction of cusp heights. After generating the NC-code, a sculptured surface was machined by five-axis end milling and cusp heights on the machined surface were measured by a three-dimensional CMM with laser scanner. From this machining test, it was found that this machining method is effective.     

Design of parts and manufacturing systems for reliability and maintainability

The design of parts and manufacturing systems can be viewed from different perspectives. This paper discusses the design of parts and manufacturing systems from reliability and maintainability perspectives. A convenient method of considering reliability and maintainability is through the use of design rules which are based on empirical and theoretical knowledge. Four design rules for improvement of reliability and maintainability of systems are presented. The design rules are proven and substantiated with numerical results. The relationship between the design for reliability and maintainability rules and design for manufacturing process rules is discussed.     

Specialized numerical control system for five-axis planing and milling center

The architecture and design features of the numerical control system for an E7106MF4 machining center are considered. This system permits five-axis machining by three-dimensional planing. Organization of the automatic electrical automation subsystem is discussed. Practical aspects of the control system are presented.     

五坐标机床数控加工程序多目标转换算法

针对五坐标数控加工设备变更引起的程序转换问题,采用基于过渡机床的间接转换模式,提出了数控加工程序在多目标机床间相互转换的方法.针对不同五坐标机床的空间结构进行坐标轴匹配性分析,建立了机床坐标系之间的对应关系,研究了后置处理和逆后置处理算法.在此基础上,构造了直线轴转换算法和旋转轴转换算法,实现了两机床间数控加工程序的相瓦转换.通过实际应用表明,所提方法可有效解决五坐标数控加工程序向多目标机床转换的问题.     

Automated intelligent manufacturing system for surface finish control in CNC milling using support vector machines

Understanding the variations in surface finish due to machining is a non-trivial task and cannot be very easily estimated even for a given set of machining parameters and operating conditions due to the complexity of interactions involved. In this work, an attempt has been made to propose an automated intelligent manufacturing system for the estimation and control of surface finish using support vector machines (SVM). SVM is very effective in mapping multi-dimensional parametric problems wherein standard analytical approaches become very complicated to handle. An intelligent surface finish control support system is built to provide assistance to the operator in a priori estimation of surface finish for a given selected set of feed rate, spindle speed and depth of cut. The estimated output can be compared by the operator with the required surface finish specification and if not satisfactory, alternate operating conditions can be defined. If found satisfactory, the operator can directly use these parameters and obtain the desired finish. Such an intelligent system will be a useful support to assist the machine operator in selecting optimum operating conditions to ensure the desired surface finish. The work carried out herein indicates that a lot of scope exists in the application of artificial intelligence techniques in mapping physical phenomena especially in the area of manufacturing wherein the inter-relationships are very complex and hence help build intelligent manufacturing support systems.     

High-efficiency technique for five-axis side milling of niemann worm wheels

Journal of Mechanical Science and Technology - Five-axis side milling technique for Niemann worm wheel teeth flank using a tapered flat-end mill is presented. Equations describing the worm wheel...     

A microcomputer-based controller for milling machines

The design and development of a microcomputer-based servo motor controller is presented. The control procedure is implemented within the microcomputer so that it can be modified easily. Indeed, the flexibility introduced by the software rather than the usual emphasis on hardware makes the control package extremely attractive for machine retrofits or the custom machine-tool market. Enhancements to a standard model of servo motor, the use of sampled-data techniques and a custom-developed interface card made it possible for one particular machine tool to achieve positional accuracies of the order of 0.0005″ at the machine's maximum feedrate of 30 in min⁻¹.     

陶瓷快速成型机整体结构及零件的设计

陕西科技大学同信技术研究所提出了层合速凝成型陶瓷零件的技术。以该技术为基础,结合层合实体成型和熔融堆积成型的特点,以雕刻机为原型进行了陶瓷快速成型机整体结构及零件的设计开发,系统地讨论分析了总体布局、结构方案的确定,以及部分零件的设计过程,并展示了采用Pro/ENGINEER Wildfire 4.0进行开发的成果。目前陶瓷材料的直接成型已经成为快速成型技术的研究热点和发展方向之一,该项目设计目标是生产成本较低,结构简单,合理可靠,易于维护,预期能为中小用户提供一种选择。     

高温合金高效铣削刀具设计及制造技术浅谈

合理选择刀具基体材料及表面涂层工艺,优化刀具结构设计及磨削工艺,提高镍基合金铣削专用刀具使用寿命及加工效率,推进航空航天、兵器船舶领域难加工材料专用刀具的国产化进程.     

Near net-shape five-axis face milling of marine propellers

We present an optimal cutter location (CL) data computation for face-milling of large marine propellers composed of CL point optimization and CL path optimization on a given tool path. The CL point optimization at a single cutter contact (CC) point is conducted by maximizing the effective radius of the face milling cutter, while the CL path optimization on a series of CC points is performed by conforming deviation of the tool-swept surface from the design surface between consecutive CL data to a given machining tolerance. The proposed algorithm was implemented and applied to the machining of a large marine propeller which proved effective from a quantitative point of view, and is used on the shop floor in a Korean ship building company.     

Optimisation of workpiece setup for continuous five-axis milling: application to a five-axis BC type machining centre

When machining complex geometries on five-axis machining centres, the orientation and positioning of the workpiece in the machine workspace are generally chosen arbitrarily by the operator from the Computer-Aided Manufacturing software. Nevertheless, these two factors have considerable influence on the machining time. The present article firstly studies the choice of workpiece orientation. Relying on analysis of the machine’s kinematic behaviour, orientations of the workpiece in the machine workspace are proposed minimising the overall distance travelled by the rotary axes. Secondly, choice of workpiece positioning in translation is studied. To this purpose, the work volume in five-axis machining is identified so as to avoid overshooting the machine travels when the program is executed. The optimum positioning is chosen to minimise the overall distance covered by the machine’s axes of translation. Finally, the proposed method provides for a workpiece setup to be adopted that minimises the distances covered by the machine axes. This leads to reduced machining time with concomitant gains in productivity and greater respect for the cutter/workpiece relative feed rate for enhanced quality.     

Process modeling and toolpath optimization for five-axis ball-end milling based on tool motion analysis

In free-form surface machining, the prediction of five-axis ball-end milling forces is quite a challenge due to difficulties of determining the underformed chip thickness and engaged cutting edge. Part and tool deflections under high cutting forces may result in poor part quality. To solve these concerns, this paper presents process modeling and optimization method for five-axis milling based on tool motion analysis. The method selected for geometric stock modeling is the dexel approach, and the extracted cutter workpiece engagements are used as input to a force prediction. The cutter entry?Cexit angles and depth of cuts are found and used to calculate the instantaneous cutting forces. The process is optimized by varying the feed as the tool?Cworkpiece engagements vary along the toolpath, and the unified model provides a powerful tool for analyzing five-axis milling. The new feedrate profiles are shown to considerably reduce the machining time while avoiding process faults.     

Tool path planning for five-axis flank milling with developable surface approximation

This paper presents a novel approach that automatically generates an interference-free tool path for five-axis flank milling of a ruled surface. A boundary curve of the machined surface is subdivided into curve segments. Each segment works as a guide curve in the design method for developable Bézier surface that controls a developable patch for approximating the surface with available degrees of freedom. Geometric algorithms are proposed for calculating consecutive patches with G¹ continuity across the patch boundary. A tapered tool can move along the rulings of these patches without inducing local tool interference as a result of their developability. The machining deviation is controlled by the surface approximation error. A machining test is conducted with the generated CL data and the result verifies the feasibility of the proposed approach. This work successfully transforms avoidance of tool interference into a geometric modeling problem and provides a simple solution. It thus demonstrates a good potential for the developable surface theory of five-axis flank machining .