【作者】 屠凤莲；

【导师】 范顺成；

【作者基本信息】 河北工业大学 ， 机械设计及理论， 2010， 博士

【摘要】 随着城市建筑楼群密集度加大,超高层钢结构工程增多,以及群塔作业施工等多种因素,大型动臂变幅塔机的使用越来越多。由于受到起升机构容绳量的限制,大中型动臂变幅塔机的吊钩装置一般采用1-2倍率变换,而涉及到奇偶倍率变换,在结构上难以实现半自动化或自动化,因此研究和开发奇偶倍率半自动变换或自动变换的吊钩装置对起重运输行业具有很大的工程实用价值。本文以奇偶倍率半自动变换吊钩装置的设计与研究为目标,在总结塔机变倍率相关知识和分析塔机变倍率装置研究现状的基础上,对该装置进行了结构设计、运动分析、静力分析、稳定性分析及动力学分析等多方面机械性能的研究,并取得了如下创新性成果:1、首次对塔机变倍率的相关知识及塔机变倍率装置的研究现状进行了归纳总结,给出了塔机吊钩装置倍率的定义,并描述了倍率的计算公式。2、完成了奇偶倍率半自动变换吊钩装置的结构设计,首次在结构上实现了奇偶倍率半自动变换。3、分析了吊钩装置在塔机不同工况下的运动轨迹;绘制了二倍率状态下吊钩装置在臂架端部附近随钢丝绳上升量的变化曲线,为变倍率时的速度控制和起升就位问题提供了理论依据和数据资料;重点研究了该吊钩装置变倍率的运动过程,绘制了运动曲线,证明了吊钩变倍率机构的合理性和可行性。4、应用弹性平面力学理论分析了吊钩装置所受的平面力问题,对内侧板进行了有限元分析,绘制了变形图和应力分布图;根据内侧板组件的特殊受力方式,应用薄板稳定性理论对其进行了弹性屈曲分析,建立了板—梁式结构的有限元模型,得到了屈曲临界载荷和相应的屈曲模态。5、完成了内侧板组件的模态分析,建立了系统动力学模型,得到了内侧板组件的固有频率和振型;完成了内侧板组件的瞬态动力响应分析,绘制了内侧板受力面节点随动载荷变化的轨迹曲线,形象、直观地反映了内侧板受力面随瞬态载荷变化的规律。本课题是针对动臂变幅塔机D800/50而研发的奇偶倍率吊钩装置,但该吊钩装置的结构及变倍率原理完全可应用于其它起重机,具有很大的实用价值。理论研究成果为奇偶倍率吊钩装置的深入研究奠定了理论基础,更多还原

【Abstract】 With the density of city buildings increasing, skyscrapers of steel structure manifolding, and many cranes having to work together, etc, large and medium luffing jib tower cranes are being used more and more. Owing to being limited by rope quantity of hoist mechanism, large and medium luffing jib tower cranes adopt commonly the 1-2 ratios hook-device. Due to relating to odd-even ratios, it is difficult to accomplish the ratios transform semiautomatically and automatically. Therefore, studying and seeking after the odd-even ratios hook-device that can transform ratios semiautomatically or automatically have great practical value to the crane industry.Aimed at designing and studying the odd-even ratios hook-device, and based on summarizing the correlative knowledge of the ratios transform and analysing study actuality of the ratios transform device, the dissertation studies this hook-device’s structure design, movement analysis, statics analysis, stability analysis, dynamic analysis, etc. The creative contributions are summarized as follows.1. For the first time, the correlative knowledge of ratios transform and the study actuality of the ratios transform device were summarized. The definition of the hook-device’s ratio is given. And the computing formula of the ratio is described.2. The structure design of the odd-even ratios hook-device is finished. For the first time this device accomplishes semiautomatically the odd-even ratios transform through the structure.3. The hook-device’s movement curves are analysed in different work-modes of luffing jib tower crane. In even ratio the device’s movement curve with rope rising is pictured near the top of the jib. It provides a theory basis and the data information for control problem of speed and hoist position when transforming ratios. The movement process of the hook-device transforming ratios is anatomized. The movement curve is drawed. It prove rationality and feasibility of the hook-device.4. The hook device’s planar forces are analysed using planar elastic mechanics theory. Inside-plate is carried out finite element analysis. The deformed picture and the stress distributing picture are described. According to special forced method, inside-plate subassembly is carried out buckling analysis making use of plate-shell’s stability theory. The finite element model of the plate-beam structure is established. The buckling loads and the modes are obtained.5. Inside-plate subassembly is carried out mode analysis. Its dynamics model is built. Natural frequencies and mode shapes are obtained. Whereafter, Inside-plate subassembly is performed dynamic analysis. Displacement graph of the node on the forced plane is drawn. It represents fluctuant curve visually that the inside-plate’s forced plane is going with dynamic load.In this dissertation, the odd-even ratios hook-device is designed for D800/50 luffing jib tower crane. But its structure and principle of the ratios transform are applicable completely to other crane, and have great practical value. The research result in theory of this dissertation will lay a solid foundation for the in-depth study of the odd-even ratios hook-device.更多还原