摘 要
我国液压工业的不断发展，行业供给能力不断增强，中低端产品有供过于求的状况。在2014年液压油缸行业实现工业总产值325.15，同比增长10.3.2011年至今，工程机械行业就增速放缓，受下游需求市场的影响。我国液压油缸行业增速也放缓了脚步。数据显示，2014年我国液压油缸营业收入262.65亿元，同比增长7.4%，增长速度下降2个百分点。
随着经济持续健康快速发展，各种重大基础设施的建设进入新的发展高潮，工程机械需求量大幅度增长。液压油缸产品作为主机的重要配件发展前景十分广阔，仅挖掘机国内年需求量将达到万余台。目前，我国液压油缸主要依靠进口，为降低成本，提高国际竞争力，国内挖掘机生产企业急需实现油缸国产化，因此液压缸销售市场十分广阔。
液压缸的设计包括液压缸活塞缸的直径及外径，液压缸活塞直径的确定，和活塞杆直径的确定，液压缸壁厚和外径的计算，缸盖厚度的确定，刚体长度的确定，缓冲装置的计算以及活塞杆稳定性的验算。根据仿真结果分析，液压缸在运行过程中速度振动较大，本论文将PID控制算法加入到系统中，采用积分分离PID控制方法对本液压系统进行了仿真分析，结果显示加入PID控制方法后系统稳定性得到了提高，具有良好的工作性能。
关键词：升降机;双缸直顶式;三级液压缸;动态仿真;PID控制
Abstract
Continuous development of China hydraulic industry, industry supply capacity growing, low-end products have an oversupply situation. 2014 hydraulic cylinder industry realized total industrial output value 325.15, an increase of 10.3. Since 2011, the construction machinery industry will slowdown, affected by lower market demand. Our hydraulic industry growth has slowed down the pace. Data show that 2014 operating income of 26.265 billion yuan of hydraulic cylinders, an increase of 7.4%, the growth rate dropped 2 percentage points.
As the economy healthy and rapid development, all kinds of construction of major infrastructure into a new surge of development, substantial growth in demand for construction machinery. Hydraulic products as a host of important parts and development prospects, domestic demand will only reach excavators thousand units. At present, China mainly imported hydraulic cylinder, in order to reduce costs and improve the international competitiveness of the domestic excavator production enterprises need to realize the localization of the cylinder, so the hydraulic cylinder sales market is very broad.
Hydraulic cylinder design, including determining hydraulic cylinder piston diameter and the outer diameter of the cylinder, OK OK hydraulic cylinder piston diameter and piston rod diameter, wall thickness and outer diameter of the cylinder calculation to determine the thickness of the cylinder head, the length of the rigid body, checking calculation buffer means and the piston rod stability. According to the simulation results of the analysis, the hydraulic cylinder during operation speed vibration is large, this paper will PID control algorithm was added to the system, using the integral separation PID control method of the hydraulic system simulation analysis showed that after adding PID control system stable It has been enhanced, with a good performance.
Keywords: elevator;-cylinder direct-top; three cylinders; dynamic simulation; PID control
目 录
