应用CNC技术提高精加工机床的加工精度及加工柔性

针对多缸柴油机机体缸套孔及离合器壳定位销孔精加工中存在的问题。应用经济型数控系统对专用机床实行机、电、液一体化控制的改造。对应用CNC技术精确设定开环控制系统的机械原点。提高传动精度及专用机床加工柔性化的方法进行了研究。     

ANALYSIS ON THE SPINNING FORCES IN FLEXIBLE SPINNING OF CONES

Flexible spinning is a new type of spinning process where spin-forming is performedwithout using a mandrel. Combining shearing and rolling processes, the calculation formulas of thespinning forces in flexible spinning of cones is presented. The effects of the main processing parame-ters, such as gripping force G applied to the blank by the inner roller, the feed rate of rollers f and theroundness radius of outer roller r_o, on the spinning forces are analyzed experimentally and theoreti-cally.     

基于解释器技术的注塑模CAD系统研究

针对传统泣塑模CAD系统的缺陷，提出并分析了新型注塑模系统的总体设计方案和3DMCAD／CAM系统构建语言，由此实现了柔性化注塑模CAD系统，包括模架、抽芯机构、浇口套等机构及其孔型的信息获取、自动生成、更新和删除。     

A network approach for modeling and design of agile supply chains using a flexibility construct

Agility can be viewed as a need to encourage the enterprise-wide integration of flexible and core competent resources so as to offer value-added product and services in a volatile competitive environment. Since flexibility is considered a property that provides change capabilities of different enterprise-wide resources and processes in time and cost dimensions, supply chain flexibility can be considered a composite state to enterprise-wide resources to meet agility needs. Enterprise modeling frameworks depicting these composite flexibility states are difficult to model because of the complex and tacit interrelationship among system parameters and also because agility thrives on many business objectives. In view of this, the modeling framework presented in this paper is based on analytical network process (ANP) since this methodology can accommodate the complex and tacit interrelationship among factors affecting enterprise agility. The modeling framework forms a three-level network with the goal of attaining agility from the perspective of market, product, and customer as the actors. The goal depends on substrategies that address the characteristics of the three actors. Each of these substrategies further depends on manufacturing, logistic, sourcing, and information technology (IT) flexibility elements of the enterprise supply chain (SC). The research highlights that, under different environmental conditions, enterprises require synergy among appropriate supply chain flexibilities for practising agility. In the present research, the ANP modeling software tool Super Decisions™ has been used for relative prioritization of the supply chain flexibilities. We demonstrate through sensitivity analysis that dynamic conditions do require adjustments in the enterprise-wide flexibility spectrum.

制造系统柔性评价方法研究

深入分析评价制造系统柔性的基本要求,并介绍柔性熵的概念,建立评价系统柔性的数学模型。通过实例分析,证明该模型对评价制造系统柔性有一定的价值。     

轿车车身结构概念模型中接头的模拟

提出了"接头单元”的概念,以车身某一立柱上接头为例,计算了接头柔度,并研究了在车身结构概念模型中模拟接头的方法.此外,还分析了接头柔度对整车刚度的影响.     

协调·弹性：新城主干道道路景观设计思考——以武汉市吴家山为例

道路景观设计以协调和弹性为原则,结合新城近远期规划,以实现新城道路弹性景观和协调城市风貌为目标,并从人性化角度分析道路交通安全通行问题。吴家山新城主干道具有距离长、道路绿化控制线宽以及现有的水资源丰富的特点。结合这些道路特点,从道路分段设计、路侧绿带设计、分车绿带设计和水网体系整合的方面来解决潜在交通问题并突显道路景观特色,同时起到净化水体、节约能源的作用。     

数控系统与数控机床技术发展趋势

随着计算机技术的高速发展,传统的制造业开始了根本性变革,各工业发达国家投入巨资,对现代制造技术进行研究开发,提出了全新的制造模式。在现代制造系统中,数控技术是关键技术,它集微电子、计算机、信息处理、自动检测、自动控制等高新技术于一体,具有高精度、高效率、柔性自动化等特点,对制造业实现柔性自动化、集成化、智能化起着举足轻重的作用。本文对国内外数控系统的发展概况,趋势功能及发展方向等诸多方面进行了阐述。     

OPTIMAL CONTROL OF THE FLEXI- BLE LINK MANIPULATOR WITH CONTROLLABLE LOCAL DEGREES OF FREEDOM

Although flexible manipulators own many potential advantages, one of their major disadvantages is the deterioration of the end-effector accuracy due to the flexibility. Therefore, how to reduce vibration is a significant problem. Inspired by the observation on the motion behaviors of animals, a new idea of decreasing motion deflection of the flexible manipulator is suggested. The concept of controllable local degrees of freedom is proposed and analyzed. By way of optimizing local motion provided by the controllable local degrees of freedom, the end-effector deflection of the flexible manipulator can be effectively decreased through dynamic coupling. The corresponding optimal method for vibration control of the flexible manipulator is put forward. The kinematic simulation is carried ant on a three-link flexible manipulator The corresponding results verify the feasibility of this method.     

Analytical studies for buckling and vibration of weld-bonded beam shells of rectangular cross-section

An approach to analytical solution is presented for vibration and buckling of thin-walled tubular beam shells typical of automotive structures, which are fabricated by joining sheet metal stampings along the two longitudinal edges with periodic spot welds, adhesive bonding, or combination of spot welds and bonding, known as weld bonding. Solutions are obtained for such beam shells of rectangular cross-section with two opposite ends simply supported. The beam shell is modeled as an assembly of the constituent walls and Levy-type formulation is used to obtain a series solution for the transverse displacement of each of the walls. The challenge of expressing the discrete point support conditions at the spot welds by a continuous function is addressed using the flexibility function approach used in literature. The flexibility function, used earlier to represent the flexibility distribution along weld-bonded edges of rectangular plates with periodic spot welds, is used here. The characteristic equations are obtained by satisfying the displacement, slope, shear, and moment equilibrium at the mating edges of the walls including the two weld-bonded edges and the compatibility conditions at the spot-weld locations. This approach to analytical solution, described here for thin-walled beam shells of rectangular cross-section, can be suitably adopted for more general cross-sections and joints along non-symmetric edges. A parametric study is undertaken to show the effect of aspect ratio of the beam shell, adhesive joint parameters, and the number of spot welds on the elastic buckling loads and the natural frequencies. Such parametric studies can be of use to designers in arriving at an optimal joint configuration of weld-bonded beam shells from buckling and vibration considerations.