数字式液压流量阀在工程机械中的应用

数字式流量阀是一种新研制开发、应用于工程机械液压系统控制方面的元件，本文以装载机液压系统为实例，对所应用的数字式液压流量阀的设计方案及其控制方式方面进行了论述．     

谈摩托车液压盘式制动器的结构设计

随着国内对摩托车液压盘式制动器需求量的不断加大,国内很多企业在模仿国外制动器的基础上开始自行研发,一些企业在没有完全理解制动器设计原理的情况下,没有经过充分试验便更改国外制动器的一些设计尺寸,从而造成设计上的一些不合理,其中最普遍的问题就是制动器的制动抱死现象.     

整体式交流发电机查线及诊断方法

基于发电机调压的原理来分析充电系的线路特点、诊断方法,综合了多种车型发电机的共性来获得一种行之有效的、快速的诊断方法。叙述如何查线、采取何种措施、应特别注意的事项等实际操作方法。     

Design of a forced control system for a dynamic road simulator using QFT

This paper presents the road simulator control technology for reproducing a road input signal to implement real road data. The simulator consists of a hydraulic pump, a servo valve, a hydraulic actuator and its control equipment. QFT (Quantitative Control Theory) is utilized to control the simulator effectively. The control system illustrates a tracking performance of the closed-loop controller with a low order transfer function G(s) and a pre-filter F(s) for a parametric uncertainty model. A force controller is designed to communicate the control signal between the simulator and digital controller. Tracking specification is satisfied with upper and lower bound tolerances on the steep response of the system to the reference signal. The efficacy of the QFT force controller is verified through the numerical simulation in which combined dynamics and actuation of the hydraulic servo system are tested. The simulation results show that the proposed control technique works well under an uncertain hydraulic plant system. The conventional software (Labview) is used to make up for the real controller on a real-time basis, and the experimental works show that the proposed algorithm works well for a single road simulator.     

Experimental investigation of nozzle cavitating flow characteristics for diesel and biodiesel fuels

This study was performed to clarify criteria for cavitation inception and the relationship between flow conditions and cavitation flow patterns of diesel and biodiesel fuels. The goal was to analyze the effects of injection conditions and fuel properties on cavitating flow and disintegration phenomena of flow after fuel injection. To accomplish this goal, it was utilized a test nozzle with a cylindrical cross-sectional orifice and a flow visualization system composed of a fuel supply system and an image acquisition system. In order to analyze the rate of flow and injection pressure of the fuel, a flow rate meter and pressure gauge were installed at the entrance of the nozzle. A long distance microscope device equipped with a digital camera and a high resolution ICCD camera were used to acquire flow images of diesel and biodiesel, respectively. The effects of nozzle geometry on the cavitating flow were also investigated. Lastly, a detailed comparison of the nozzle cavitation characteristics of both fuel types was conducted under a variety of fuel injection parameters. The results of this analysis revealed that nozzle cavitation flow could be divided into four regimes: turbulent flow, beginning of cavitation, growth of cavitation, and hydraulic flip. The velocity coefficient of diesel fuel was greatly altered following an increase in flow rate, although for biodiesel, the variation of the velocity coefficient relative to the rate of flow was mostly constant. The cavitation number decreased gradually with an increase in the Reynolds number and Weber number, and the discharge coefficient was nearly equal to one, regardless of cavitation number. Lastly, it could not observe cavitation growth in the tapered nozzle despite an increase in fuel injection pressure.     

论述不同地质吹填区域采用不同强夯方式的地基处理

分析了吹填形成的码头堆场地质构成及强夯地基处理方式的特点,针对鲅鱼圈港区吹填形成的不同地质构成区域特点,介绍了防止大面积堆场产生不均匀沉降所采取的强夯处理措施。     

介绍3种多功能集成电路调节器

多功能集成电路调节器不但具备基本的调压功能,还具备充电指示灯控制、保护、故障诊断等功能。本文分析3种多功能集成电路调节器的结构及工作原理,介绍采用多功能集成电路调节器的优点。     

液压悬置动特性实验分析及模型修正方法研究

在综合分析现有悬置非线性数学模型的基础上,重点分析了惯性通道弯管损失系数对悬置动态性能的影响,建立了包含惯性通道弯管损失系数的更精确的数学模型,并探讨了悬置及橡胶主簧动态、静态特性的试验测试方法,建立了相应的测试平台,对相同工况下液压悬置和橡胶主簧动、静态特性进行了测试及对比分析。将橡胶主簧的实验数据应用于所建的模型中,仿真结果和实验分析表明本模型具有更高的精度。     

键合图理论在汽车动力总成液力悬置系统建模与仿真中的应用

本文在介绍键合图理论的基本原理和特点的基础上,重点阐述了键合图方法如何应用于汽车动力总成液力悬置系统的建模与仿真。     

自升式风电安装船液压销孔式升降系统研究

上海振华重工为某用户设计建造的1000t自升式风电安装船采用的目前国内最先进的双液压升降形式的液压销孔式升降系统。本文对该升降系统的总体结构、特点、主要技术参数、功能及组成、各工况下的工作原理、具体应用方案等方面进行了系统、深入地研究和分析,并总结了该升降系统取得的技术效果,为今后类似项目或连续式双液压升降的升降系统的进一步研究与设计奠定了基础。