基于神经网络的金属切削毛刺专家系统的研究及应用

机械加工中毛刺的形成与存在影响、制约着精密与超精密加工和自动化加工技术的发展。基于神经网络理论,构建并开发了金属切削毛刺专家系统(Ujs),通过对神经网络的设计,并作为推理机制,以数据库为训练样本,建立了毛刺形态、尺寸与切削条件之间的映射模型,应用于金属切削毛刺的控制及预报。结合车削实验,比较了系统预报结果与实验结果,取得了较好的吻合。神经网络专家系统的建立为解决毛刺预报与控制提供了一条有效的途径。     

金属切削毛刺数据库系统的设计

毛刺的产生和存在是金属切削加工中普遍存在的问题 ,它直接影响了工件的加工精度及质量。基于数据库和Java ,研究了金属切削毛刺数据库系统的设计 ,实现了切削毛刺数据的管理、切削毛刺类型与尺寸大小及加工参数的查询 ,进一步丰富和完善了金属切削毛刺的预报与控制理论。     

金属切削毛刺分类体系的研究及其应用

将金属切削毛刺生成同切削运动联系起来，提出并建立起切削运动－刀具切削刃毛刺分类体系，清晰地给出影响毛刺生成及变化的主要因素。将该分类体系应用于车削、钻削和磨削加工，表明切削运动－刀具切削刃毛刺分类体系定义明确、完整。简便易行。     

金属切削毛刺的预测预报技术研究

系统概括了国内外时金属切削毛刺的预报预测研究现状,分析了有限元法在毛刺形成过程、形态度尺寸大小和界限转换条件的定量或定性预测预报中的具体应用,为系统深入地研究切削毛刺提供了理论基础.     

少无毛刺切削技术的研究进展

在系统概述国内外少无毛刺切削加工技术研究进展的基础上,根据机械加工实际需要,给出了主动控制或减小金属切削毛刺的基本原则,探索出少无毛刺的主要途径。此外,分析了几种切削加工技术的具体应用。指出了目前尚需解决的一些主要问题,确立了今后深入开展金属切削毛刺研究的方向。     

控制切削毛刺的基本措施

金属零件在切削加工过程中常会产生毛刺，毛刺的存在将严重地影响零件或产品的质量。影响毛刺生成的因素很多，如何防止和减少金属切削毛刺，应根据具体情况，采取相应措施。现就这一问题作一简要探讨性综述。一、从零件设计上避免生成毛刺1．选择合适的工件材料工件材料的物理机械性能对毛利的生成有很大影响，如变形硬化指数，延伸率，硬度和抗拉强度等。因此，在零件设计时，在满足强度要求的条件下，应尽可能的选用变形硬化指数和延伸率较小的材料，以减少金属切削加工时毛刺的生成。2采用合理的零件结构形状在金属切削加工中，毛刺主要…     

金属切削毛刺生成机理的研究及其发展

对国内外金属切削毛刺生成机理的研究沿革及现状进行系统的概述与分析，指出金属切削毛刺研究中尚待解决的主要问题及其发展前景。     

金属切削毛刺形成与控制技术研究进展

本文系统概述了国内外对于毛刺形成机理及控制技术的研究进展,重点阐述了预测毛刺形成的解析模型和有限元模型、毛刺形成过程的实验研究以及控制毛刺形成的加工工艺和非标刀具,分析了亟待解决的问题,指出了金属切削毛刺形成机理和控制技术研究的方向.     

金属切削毛刺预报研究现状分析

阐述了金属切削毛刺形成预报研究的背景,并国内外学者的研究现状进行了分析研究,并且做出了比较,再在总结与归纳出金属切削毛刺预报的研究现状中尚存在的一些问题的基础上,指出在科技不断发展的现在,对金属切削加工技术的要求也越来越高,由于金属切削毛刺研究说涉及的领域很多,所以也给研究带了了新的机遇与挑战。最后指出了解决金属切削毛刺形成预报的关键问题和研究的发展方向。     

金属切削毛刺的预测预报技术研究

金属切削毛刺是切削加工中产生的常见现象,它严重地影响着产品的精度和使用性能,有必要对毛刺的预测预报进行深入系统的研究.系统地概括了国内外对金属切削毛刺的预报预测研究现状,分析了有限元法在毛刺形成过程、形态及尺寸大小和界限转换条件的定量或定性预测预报中的具体应用,为系统深入地研究切削毛刺奠定了坚实的理论基础.     

Investigation on the burr formation mechanism in micro cutting

It is desirable to minimize burr formation for improving part quality. This paper presents an investigation on the burr formation mechanism in micro cutting by taking into consideration the stress distribution around the cutting edge arc. The influences of the uncut chip thickness and the cutting edge radius on burr formation were investigated. Poisson burr is attributed to the side flow of the stagnation material at the bottom of the cutting edge arc. The stress distribution at the cutting edge arc has great influence on Poisson burr formation. The burr height decreases to the minimum value and then increases with reducing the uncut chip thickness due to the change of the maximum stress distribution. An optimum machining strategy also is suggested in micro milling of snake-shaped groove microstructure.     

钻削毛刺控制专家系统的开发及应用

金属的钻削加工中棱边的形成是一个非常复杂的过程，很难建立起其数学模型。为充分利用其实验研究的成果，应用钻削毛刺控制图表(DBCC)的方法开发出钻削毛刺控制的专家系统，对钻削加工过程及棱边的形态进行预测和预报，并对零件棱边的形成进行动态仿真。本系统的开发实现了钻削毛刺形态及尺寸的预报，提供了控制钻削毛刺生成的方法，具有十分重要的理论意义和实际应用价值。     

金属切削中如何选择切削液

概述了切削液的种类和性能,介绍了目前切削液的使用情况,重点探讨了在不同的材料、不同的切削方法、各种常见刀具及良好的经济效益下选择切削液的基本原则.     

An integrated manufacturing information system for mass sheet metal cutting

In order to reduce manufacturing cost and to improve the operational efficiency, some factories in the sheet-metal-related manufacturing industry centralize the production and management of sheet metal cutting. To support the centralized mass manufacturing paradigm, this paper presents an integrated manufacturing information system to achieve the high utilization of raw sheet material, lower the manufacturing cost, as well as to improve the operational efficiency and production management. The system architecture and some key technologies to implement this system are investigated, based on which, the whole information system is developed. This system integrates the functions of sheet metal part modeling and unfolding, nesting planning, automatic and interactive nesting, cutting process planning, NC-programming, off-line processing simulation and on-line monitoring. The system has been successfully utilized in industry, and an example of its application is described in the paper.     

Effect of polar organic substance on burr formation in orthogonal cutting

The initiation of burr formation is characterized by the initial negative shear angle and the initial tool distance which are obtained from the minimum energy principle and energy conservation at the chip/burr transition point. Specially in this report the rollover burr is dealt as a specific case of the chip formation process in the final stage of cut, which the tool moves toward the end of workpiece. The purpose of this paper is to experimentally invesigate the burr formation mechanism near the end of cut by using a copper with various cutting conditions and tool geometries, and the influence of the surface active medium, that was used to reduce the burr size and improve the machinability, upon the mechanism of burr formation in the orthogonal cutting using the milling machine.     

面向CIMS的板类零件下料工艺系统

介绍了一个以优化排样为核心，为企业板类零件下料生产提供有效整体解决方案的集成工艺设计系统。提出了基于企业局域网、面向GIMS的总体集成设计方案，开发了以优化排样为核心的下料工艺设计流程，设计并实现面向多种下料工艺的优化排样算法。最后以广西某集团为对象介绍了上述思路的具体实施方案及实施效果。     

金属切削加工过程的有限元数值模拟

运用有限元方法对切削过程进行数值模拟,分析不同切削速度在切削加工过程中对切削温度及切削力的影响,从而有助于深入了解加工过程,合理选择加工工艺参数。     

柔性制造系统设备故障诊断专家系统的开发研究

通过建立单元子知识库、行为子知识库和故障树子知识库,将复杂的故障信息进行有效分解,并利用知识库中的管理子系统管理各子知识库;采用正反推理混合方式以及单元推理、行为推理和故障树推理的方式,提高故障诊断效率。     

Characterization and modeling of burr formation in micro-end milling

Mechanical micromachining is increasingly finding applications in fabrication of components in various fields, such as, biomedical devices, optics, electronics, medicine, communications and avionics. In order to ensure adequate functionality, there are stringent requirements for form and finish in case of biomedical devices like cochlear implants and metallic optics. This necessitates that the post machined surface must be burr free. To address these issues in micromachining, this paper presents results of an experimental study to investigate the influence of main process parameters i.e. speed, feed rate, depth of cut, tool diameter and number of flutes on the formation of the various types of burrs i.e. exit burrs and top burrs produced during micro-end milling operation. The experiments performed using Taguchi method shows that three types of burr formation mechanisms prevail during micro-end milling operations; these are: lateral deformation of material, bending and tearing of the chip. Also, three types of burrs were observed include: Poisson burr, rollover burr in down milling and tear burr in up milling. Further, it is observed that the depth of cut and the tool diameter are the main parameters, which influence the burr height and thickness significantly. However, the speed and the feed rate have small to negligible effect on the burr thickness and height. Besides the experimental analysis, the paper presents an analytical model to predict the burr height for exit burr. The model is built on the geometry of burr formation and the principle of continuity of work at the transition from chip formation to burr formation. Note that prediction of burr height in micro-end milling is extremely challenging due to the complex geometry of material removal and microstructural effects encountered during cutting at that length scales. The model fares well and the prediction errors range between 0.65 and 25%.     

Experimental investigations of sideward burr formation in rotary machining

Burrs can be formed on the feed mark ridges and the edges of the machined parts in machining operations. These burrs are undesirable in terms of the surface quality, the precise dimensioning of the machined parts and the safety of operators. This paper demonstrates the effectiveness of using a rotary tool on minimizing the sideward burr formation in machining. In particular, the experimental relationships between the size of sideward burr and the cutting parameters (including tooling mechanism) are established first in rotary machining. Methods to control the size of sideward burr are then explained. The possible application of a rotary tool for deburring operations while engaged in machining is also explored.