加工中心生产开关面板定叶片零件数控加工方法

文章以“开关面板定叶片”零件为项目，在零件因批量小而不适合开发压铸模的前提下，从零件的结构特征分析入手。设计专用夹具完成零件的正反面装夹，对采用合理的加工工艺在加工中心上完成零件的加工进行了探讨。     

头盔镜片模具型芯的5轴数控加工

本文介绍了头盔镜片模具型芯零件的数控加工方法。实践表明,采用5轴加工中心来加工高精密零件,在无需专用夹具的情况下一次装夹就可完成加工,可以获得更高的切削效率和更好的加工表面质量。     

加工中心批量生产门锁把零件数控加工方法与实践

笔者以门锁把零件为项目,在零件因批量小而不适合开发压铸模的前提下,对如何利用加工中心,采用合理的加工工艺及科学的装夹方法批量加工生产该零件进行了探讨。从零件的结构特征分析、批量生产的方案、装夹底板的加工、零件的正反面装夹及切断等关键问题上较详细进行了论述。     

循环程序在航空零件高效批量生产中的应用

零件加工在试制阶段与批量生产阶段是完全不同的加工模式,但是在实际加工生产过程中,往往发现批量生产的零件,依然采用试制阶段的加工模式。笔者通过应用研究,利用自动编程软件编制循环数控程序,把批量生产零件中的刀具规格、切削参数和走刀路线等固化在程序中,经过试验加工,证明循环数控程序减少了操作者的劳动量,提高了机床的使用率和零件的加工效率,尤其是在零件大批量生产过程中,这种优势更加明显。目前该循环数控程序加工模式已在笔者所在公司内盘类零件加工中得到了应用,并取得了很好效果。     

夹紧顺序、夹具布局和夹紧力对装夹变形影响与同步优化分析研究

为减小工件装夹变形,提高薄壁件加工精度,以薄壁零件装夹变形最小化为目标 函数,通过遗传算法和有限元方法相结合,提出夹紧顺序、装夹布局和夹紧力同步分析方法。用 该方法对一航空薄壁零件装夹进行优化分析,优化结果与经验设计及传统分析结果进行对比,有 效地降低了工件因装夹不当引起的变形,验证了夹紧顺序、夹具布局和夹紧力同步优化方法的 有效性。     

数控车床生产加工实用技巧三例

一、GSK系统数控车床偏移工件坐标系连续多次加工法在机械车削加工中常常遇到圆柱形且长度较短的零件,这类零件采用数控加工,加工效率高,精度高,但辅助装夹毛坯时间对生产效率影响较大。如图1a所示是某企业所接到的某产品配件(旋盖),批量要求较大,产品材料为铝,可直接用空心管作为毛坯,在数控车床上加工完成。     

模具型芯的数控加工工艺分析

数控加工工艺是指采用数控机床加工零件时,所运用各种方法和技术手段的总和,应用于整个数控加工工艺过程.由于数控加工具有加工效率高、质量稳定、对工人技术要求相对较低、一次装夹可以完成复杂曲面的加工等特点,所以,数控加工在模具制造行业的应用越来越广泛,地位也越来越重要.数控工艺设计的好坏将直接影响数控加工尺寸的尺寸精度和表面质量、加工时间的长短、材料和人工的耗费,甚至直接影响加工的安全性.下面通过实例对典型模具成型零件的数控加工工艺进行分析.     

如何在经济型数控车床上实现自动钻孔功能的探讨与实践

为解决套筒类零件在经济型数控车床上用刀架装夹钻头通过程序自动钻孔的加工问题，设计了一种可装夹多种直径尺寸钻头的夹具，即保证了加工质量稳定、可靠，又提高了生产率，改善了劳动条件。     

普通铣床铣削轴上键槽工艺的探讨

阐述了轴类零件键槽的装夹方法、铣刀对中心的方法、加工及检测。     

浅议薄壁轴承套圈的数控车削加工技巧

薄壁轴承套圈的数控车削技巧包括零件装夹变形、受切削力变形等难点分析,通过夹具改装等解决方法来保证零件的加工精度,提高生产效率。夹具的合理改装,切削参数的优化处理使的薄壁轴承套圈的数控车削的加工精度得到了有效保障。     

炸药件加工真空装夹安全性计算

为解决真空装夹炸药件加工的安全问题,对炸药件真空装夹加工过程进行三维动力学分析.综合考虑重力、离心力和切削力等因素的影响,建立静态、转动态与切削态下真空装夹安全因数的计算方法和计算公式;采用C++编程,开发安全因数计算程序,实现炸药件加工真空装夹安全性的快速、自动计算.该方法能为工艺规划与工装设计、提前预防或减少炸药机...     

Digital twin-driven clamping force control for thin-walled parts

Clamping quality is one of the main factors that will affect the deformation of thin-walled parts during their processing, which can then directly affect parts’ performance. However, traditional clamping force settings are based on manual experience, which is a random and inaccurate manner. In addition, dynamic clamping force adjustment according to clamping deformation is rarely considered in clamping force control process, which easily causes large clamping deformation and low machining accuracy. To address these issues, this study proposes a digital twin-driven clamping force control approach to improve the machining accuracy of thin-walled parts. The total factor information model of clamping system is built to integrate the dynamic information of the clamping process. The virtual space model is constructed based on finite element simulation and deep neural network algorithm. To ensure bidirectional mapping of physical-virtual space, the workflow of clamping force control and interoperability method between digital twin models are elaborated. Finally, a case study is used to verify the effectiveness and feasibility of the proposed method.     

An approach to enhancing the intelligence of a three-fingered automated flexible fixturing system by using adaptive control theory

A new approach to clamping workpieces for the machining process has been developed. The new approach is based on the identification of the workpiece stiffness, during the machining process, which enables the fixturing system to determine whether the clamping force should be changed. Using this approach, a three-fingered intelligent automated flexible fixturing system for planar objects has been successfully designed and implemented. The conventional and traditional clamping methods use a hydraulic vise to clamp workpieces with a fixed amount of clamping forces. This often causes the workpieces to deform under such force, thus contributing to machining error. It is therefore desirable to control the clamping force according to the progress of the machining process. The implementation of this approach to the three-fingered automated flexible fixturing system enhances the system’s ability to achieve intelligent clamping force control and deal with abnormal machining, thus making the system intelligent. A thin ring-shaped workpiece was successfully used as an example to demonstrate the feasibility and validity of this approach. It also demonstrates that the developed system can be used in the highly automated manufacturing system of the future.     

基于GA和FEM的夹具布局和变夹紧力优化设计

通过夹具布局和夹紧力大小的优化可以提高薄壁件加工精度．建立了夹具布局和变夹紧力分层优化模型．首先,以工件加工变形最小化和变形最均匀化为目标函数,对夹具布局进行优化设计;其次,基于优化的夹具布局对变夹紧力进行设计．采用有限元法计算工件的加工变形,加工变形求解时综合考虑了接触力、摩擦力、切削力、夹紧力和切屑的影响．采用遗传算法求解优化模型,获得优化的夹具布局和变夹紧力．通过实例分析,验证了分层优化设计方法可以进一步减小工件加工变形,提高加工变形均匀度．     

Optimization of a robotized cell with redundant architecture

This article presents a multi-objective optimization approach used for redundancy resolution in a robotized cell. The cell is dedicated to finishing operations, by machining and polishing, on large cast aluminum parts. The objectives are to improve machine capability and kinematics capacity. We first formalize the main constraints related to the process and to the cell. We then describe our optimization, kinematics and precision criteria as well as the multi-objective method developed. This method has been verified by simulation and the results have been validated on industrial parts. The study was carried out in collaboration with the Société des Fonderies d'Ussel (SFU), part of the Alcan group, specialized in high technology aluminum molded parts. The applications relate mainly to aeronautical, energy and transport activities.     

Stability of Workpiece in Feature－Based Fixture Planning System

Analyzed the issues of stability of workpiece during clamping and machining,Discussed classification of the stability problem according to the forces acting on the part in the commonly used machining processes;gave the methods of calculating clamping force and measures to guarantee the stability of workpiece in the feature-based fixture planning design system.     

Stability ofWorkpkce Setup in Feature-Based Fixture Planning System

Analyzed the issues of stability of workpiece during clamping and machining. Discussed classification of the stability problem according to the forces acting on the part in the commonly used machining processes; gave the methods of calculating clamping force and measures to guarantee the stability of workpiece in the feature-based fixture planning design system.     

A method to minimize the workpiece deformation using a concept of intelligent fixture

Manufacturing processes are commonly affected by the low stiffness of the components limiting the quality and precision of the final product. Precision is one of the most important issues in the machining process, and the main cause for rejection is the part static deformation and the dynamic vibrations. The static deformation is mainly affected by two factors: deformation due to clamping and process forces, and geometrical distortions due to material removal and residual stress relieving during processing.The deformations caused by the clamping in the fixture are normally associated to existing distortion in the raw workpiece due to previous manufacturing processes and to the clamping forces. These problems lead to uncertainties in the set-up process, hindering the fixture functions, the achievement of a right positioning of the workpiece and the avoidance of deformations due to clamping forces.This paper presents an analysis to identify the causes of the static deformations during clamping and a method to correct the geometrical distortion and deformation of a clamped workpiece by the evaluation of the reaction forces in the selected relevant clamping points. It covers the design and validation of an active clamping unit to minimize the deformation produced by the fixture that could affect the machining process. The developed clamping unit presents an alternative to combine the locator and the clamper in a single component that controls the reaction force and the deformation of the workpiece in the clamping point, and it performs the positioning of that point to minimize the distortion of the workpiece. The clamping unit was verified in laboratory conditions and then tested in an industrial application, evaluating the capabilities related to positioning and reaction force control.     

Model testing of fixture–workpiece interface compliance in dynamic conditions

This paper is focused on the problem of compliance of interface between clamping/locating fixture elements and workpiece, under dynamic loads during machining. In contrast to previous investigations, the authors have developed a special device dedicated to testing of physical models which represent clamping/locating elements and workpiece. This device allows optimization of a large number of input parameters which are critical to interface compliance. It was used in experimental investigations to establish the impact that the radius of the spherical tip of a clamping/locating element has on the interface compliance and load capacity. The results of experimental investigation show that, under certain conditions, the clamping/locating elements with larger-radius spherical tips provide significantly lower interface compliance. Future investigations should be aimed at finding optimum macro- and micro-geometries of contact interface, as well as the selection of materials for clamping/locating elements.