文档介绍：摘要
液压打桩锤是用于建筑、桥梁、码头等桩基础施工中打入预制桩的桩工机械。随着科学技术的进步,预制桩施工机械由落锤、汽锤、柴油锤,发展到了液压打桩锤。用液压打桩锤打桩,可以调整撞击应力波波形,减小应力峰值,延长有效作用时间,是一种比较理想的预制桩施工机械,目前在发达国家已被广泛使用,并形成了系列化。本文应用冲击机械系统动力学分析打桩过程中锤体与桩撞击时应力波的产生、传播以及该波对沉桩过程的影响。认为与桩等波阻的细长状锤体能够产生理想的应力波波形;在桩锤重量一定的情况下,可针对不同的地质情况和桩,通过选择不同刚度的桩帽和桩垫与其匹配来提高打桩效率。本文对双缸双作用液压扣一桩锤液压系统的结构和工作原理进行了深入的研究,并在此基础上设计出六吨双缸双作用液压打桩锤的液压系统和电控系统。由于液压打桩锤液压系统是一个复杂的非线性系统,本文采用功率键合图法建立液压打桩锤上行、下降的键合图模型和状态空间方程,通过四阶龙格---库塔法和预估---校正法相
结合编制了仿真程序对状态空间方程求解,在Mat lab 6. 5中进行液压系统的动态仿真,获得液压打桩锤运动过程中压力、位移、速度、加速度等随时间变化的曲线图。此曲线图方便了对液压系统动态特性分析,为液压系统的设计和参数优化提供了有益的借鉴。最后,在深入分析双缸双作用液压打桩锤控制系统的功能要求后,采用了以现代计算机技术为基础的新型工业控制装置-PLC可编程控制器,设计出了双缸双作用液压打桩锤的电器控制系统。PLC体积小、功能强、可靠性高、能适应建筑施工机械恶劣的野外环境。通过PLC电控系统可以准确选择不同的上升、下降和保压时间,使得液压打桩锤具有不同的下打高度,从而获得不同的打击末速度,提高了液压打桩锤对不同土壤的适应能力。
关键词:双缸双作用液压扫一桩锤;数值仿真; 可编程控制器。
ABSTRACT
Hydraulic pile hammer is one of the pile driving machines that drive prefabricated piles into the ground in the construction of pile foundation such as construction, bridge, dock, etc. With the development of science and technology ,the prefabricated pile driving machines evolve from block hammer ,steam-hammer ,diesel hammer to hydraulic hammer .Hydraulic pile hammer is one of ideal prefabricated pile driving machines because it can adjust stress waveform ,decrease stress peak value, prolong effectual action when it drives piles .Hydraulic pile hammer is used widely and formed series in developed countries now. Mechanical impact dynamics is used to analyze the production and spread of stress wave when hydraulic pile hammer blows piles, the stress wave influence the course of driving pile. Slender hammed that is equal to wave resistance of the pile can bring ideal stress waveform. When the hammer weight is constant,efficiency of driving pile can be increased by means of selecting drive cap and cushion pad of different rigidity to match the hammer according to various geological condition and the pile. The structure and principium of hydraulic system of double-acting hydraulic pile hammer