【作者】 杨敬；

【导师】 权龙；

【作者基本信息】 太原理工大学 ， 机械电子， 2013， 博士

【摘要】 目前,液压挖掘机节能研究主要体现在：提高柴油发动机、液压元件性能,改进液压系统和改善柴油发动机-液压系统-执行器的功率匹配,以上措施具有一定的节能效果,但由于液压挖掘机负载变化频繁、波动较大,柴油发动机常常工作在高速小负荷工况,燃油消耗较高,所以为了改善小负荷时柴油发动机的经济性,减少液压挖掘机整机燃油消耗,提出在液压挖掘机中采用柴油发动机停缸控制的能量管理思想。论文分析了液压挖掘机的基本组成和工况特点,概述了试验样机YC60型挖掘机的主要技术参数,阐述了样机采用的恒功率泵的工作原理。由于试验样机液压系统采用LUDV系统,其压力补偿阀在多路阀后端,当系统流量饱和时,液压泵的供油量不能满足多执行元件需要时,各节流孔前后压差相应减小,使得压差仍然相等,各执行元件的流量仍取决于阀开口面积的大小,故结合样机多路阀、液压泵、液压执行元件的相关参数,建立了YC60挖掘机液压系统仿真模型。分析了柴油发动机速度特性、负荷特性、调速特性,明确了柴油发动机动力性、经济性的主要指标以及克服外负载的能力。由于采用微分方程建立的柴油发动机数学模型,仿真精度较高,但工作量大,结果分析困难,所以在本课题巾利用AMESim软件进行了建模,利用IFP-Engine元件库,建立准确的柴油发动机模型,通过设置系统参数,对柴油发动机的相关性能进行了仿真分析。液压挖掘机工作过程中得各工作装置的运动学分析和状态辨识是挖掘机工作分析的重要组成部分,有效地辨识判断整机的工作状态与负载,是实现液压挖掘机的柴油发动机停缸优化柴油发动机工作区域的重要前提,因此本课题的任务之一是完成液压挖掘机工作状态的辨识。目前液压挖掘机工况及负载的判断的方法有两种：一种是通过图像处理技术辨识挖掘机开挖工况的外形及特征,另一种是对挖掘机液压系统的压力值处理来判断负载。采用图像处理技术缺少了挖掘机铲斗与工作介质之间的作用关系的有效判断,而采用液压系统压力值缺少了工作装置位姿的有效数据。在挖掘机同样的位姿状态下,由于挖掘对象的不同甚至可能是空载,液压系统的压力值是不同的。因此本课题将液压挖掘机的各工作装置的位姿与液压系统的压力相结合,对挖掘机的工作状态进行辨识,即通过挖掘机回转马达、铲斗油缸、斗杆油缸、动臂油缸各腔安装压力传感器,检测挖掘时各腔压力来判断挖掘机的负载大小,同时在三个油缸处安装位移传感器,检测各油缸活塞位移实现对工作装置运动轨迹跟踪。对于目前在液压挖掘机上液压泵—柴油发动机匹配的节能方案所存在的在挖掘机小负荷时柴油发动机处于高转速、小负荷工况远离其最佳经济区域,所造成的油耗较高的问题,本课题采用了柴油发动机停缸节油技术,通过对挖掘机在一个工作循环内的能量消耗的理论分析,同时结合柴油发动机全部气缸工作和柴油发动机1缸断油停缸工作时的万有特性曲线,明确了在液压挖掘机上采用柴油发动机停缸技术的节油机理,根据柴油发动机停缸节油机理和挖掘机工作循环的能量消耗、动力系统各参数的变化规律,提出基于整机状态辨识的柴油发动机停缸节油控制策略。在挖掘机停缸动力系统具体控制策略的基础上,针对挖掘机动臂下降、空载回转等工况,对挖掘机的动力性、经济性进行对比试验和分析。液压挖掘机在实际工作中,常会出现挖掘机短时停止工作但柴油发动机不停车的状态,为降低此种状态时整机的燃油消耗,采用液压挖掘机自动怠速技术,但怠速工作时柴油发动机的燃油消耗并不向外做功,所以尽量减少怠速时燃油消耗,所以在研究内容中针对液压挖掘机柴油发动机怠速工作时燃油消耗的问题,进行了怠速停缸经济性试验。针对挖掘机回转过程工作循环时间长、能量消耗大的特点,以回转机构转动惯量为出发点对挖掘机回转过程进行试验研究和分析,并在挖掘机满载、小转动惯量回转时,柴油发动机采用停缸技术后,进行整机经济性试验。试验结果表明：采用柴油发动机停缸节油技术,有利于使柴油发动机在部分负荷时接近高效率区,在满足整机动力性的前提下,燃油消耗量下降。更多还原

【Abstract】 Presently, energy-saving hydraulic excavators study is mainly reflected in improving the performance of diesel engine and hydraulic components, improving the hydraulic system and improving power match among diesel engine, hydraulic system and actuators. But because the big variable load in frequent, the diesel often works under the condition of high speed and low load, the fuel consumption is high. So to improve the economical efficiency of the fuel engine and to induce the consumption of the whole machine, the energy management thought that is to control the operating state of the diesel engine’s cylinder is put forward.The basic components and working condition of the hydraulic excavators are analyzed. The main technical parameters of the machine (YC60-7made of yu-chai) are described in this paper. The working principal of constant output pump is elaborated adopted by the research prototype. Because system LUDV pressure-compensated valve is behind multi-way valve, when the rate of flow of the system saturated, the oil supply of oil hydraulic pump cannot meet the demand of excessive executive components need. The differential pressure between the head and the end of all the orifices becomes relatively lighter. That makes differential pressure keeping equal while the rate of flow of all the excessive executive components still depends on the opening area, it is widely used in small hydraulic excavator, so considering the relevant parameter of the multi-way valve, oil hydraulic pump, and hydraulic executive components of the prototype, systematic model of oil hydraulic excavator is set. Speed, load and speed regulation characteristics of the diesel engine are analyzed, the dynamic and economic leading indicators and the ability to overcome outer laden of the diesel engine. If we use math model of diesel engine set up by differential equation, the simulation precision is high, but the workload is too heavy and the result is too difficult to analyze. So here software AMESim is used to set the model. IEP-Engine component library is used to set precise diesel engine model. And the relative characteristics of the hydraulic excavator are emulation ally analyzed by setting system parameter.The kinematics analysis and state identification of all the working devices during the working process of the hydraulic excavator are important components of hydraulic excavator working analysis. Stating and judging the working state and load of the overall unit effectively is a crucial precondition to make the cylinder optimize the hydraulic excavator’s diesel engine working area, so to achieve hydraulic excavator’s working state identification is one of the aim of this paper. Presently there are two methods to do it:one is to state the outline and the characteristics of the working condition of the hydraulic excavator by image processing. The other one is to estimate the load by managing the pressure value of the hydraulic excavator system. The first one is lack of effective judgment of the function relation between the scraper pan and the working medium while the second one is lack of effective statistics of the working devices pose. Under the same pose, the pressure value of the hydraulic system is different because the objects are different, even empty. Here all the working devices poses of the hydraulic excavator and the pressure of the hydraulic system are combined to identify the working statement of the hydraulic excavator. That is by excavator slewing motor, bucket cylinder, bucket rod oil cylinder, the movable arm cylinder cavity pressure sensor installation, testing the pressure determining the load excavator digging size. At the same time install displacement sensor at three cylinders to detect the oil cylinders piston displacement in order to achieve the tracking of the working devices motion trajectory.On account of hydraulic pump-diesel engine matching scheme have the problem of high fuel consumption when the hydraulic excavator works under low load as well as the engine works under high speed, low load condition, the saving technology of stopping the diesel engine cylinder is adopted in this paper. Theoretical analysis of fuel consumption of a whole operating cycle combined with the engine universal performance characteristics map when the engine works under all cylinder or one deactivation, the fuel saving mechanism about cylinder deactivation is clear. On the basis of the fuel saving mechanism about cylinder deactivation, the fuel consumption of a whole operating cycle and changing law of parameters of Dynamic System, the fuel-saving control strategy about cylinder deactivation based on complete appliance condition identification is advanced.On the basis of fuel-saving control strategy about cylinder deactivation, we carry out the comparison test and analysis about excavator power performance and economical about the boom down, no-load rotating conditions. In practical work, hydraulic excavator often appears short-term state to stop working, but not to stop the diesel engine. So in such the state, the auto-idling technology for hydraulic excavator is used to reduce fuel consumption,but this fuel consumption is out of doing work, it is necessary to minimize idling fuel consumption. In this study on hydraulic excavator diesel engine idling work cylinder deactivation, economic comparison test are operated.Considering the feature of long time and high fuel consumption rotating, we carry out the test about roting and do the economic experiment using the technology of cylinder deactivation when the machine worked under the condition of full load and small moment of inertia of rotating.The test results showed that it helps diesel energy working quite close to high efficiency area and on the premise of function, it decreases fuel consumption.更多还原