单缸柴油机喷油系统的模拟计算与试验研究

利用AVL-HYDISM模拟软件建立了1105柴油机喷油系统的仿真模型,模拟了此柴油机标定工况下的喷油性能,从高压油管泵端压力以及嘴端压力两方面与试验值进行了比较,同时计算得出了样机燃油喷射规律以及压力室油压.分析了样机不足,通过改进供油凸轮使得燃油喷射压力得到提高.     

柴油机电子油门传感器的线性优化

理论上分析了影响电子油门传感部件线性度的关键因素：电子油门传感部件径向磁场磁感应强度.通过对影响电子油门传感部件径向磁场磁感应强度的各个因素：初级线圈长度和半径、偏心圆盘偏心矩和半径、初级激励电压的分析.提出了各个因素优化来提高电子油门传感部件线性度的方法,得出了电子油门传感部件最佳线性度的性能参数.并对与其匹配的信号调理电路进行了最佳线性优化.依据柴油机电子油门控制系统模拟实验装置平台,对优化后的油门传感器进行了柴油机加减负荷模拟实验,并进行了误差分析.结果表明：柴油机电子油门控制系统的动态响应达0.23 s,线性度为0.38%,完全满足电子油门控制系统正常工作的要求.     

柴油机连杆的动态应力分析及优化设计

根据连杆在柴油机工作过程中的受力特性,建立某型柴油机连杆的有限元模型.基于瞬态响应特性分析理论,利用有限元分析软件ANSYS计算出连杆在一个运动周期内的应力分布曲线.分析过程中,借助于函数进行相关载荷的动态施加,使得计算结果更具真实性.并基于优化设计理论和瞬态分析结果对连杆进行优化设计.结果表明:该型柴油机连杆满足强度、刚度的要求;优化设计后,连杆的质量可减少18％.     

电控单体泵柴油机燃油喷射控制策略

电控单体泵由电控泵喷嘴发展而来,由于在电控泵与喷油器之间加入了高压油管,使电控单元从发出喷油信号到燃油喷入汽缸的时间延迟加长.针对该特点,以及考虑到程序计算时间、电磁阀响应特性等因素对喷油正时的影响,设计了喷油正时控制策略.试验结果表明,电控单元可按喷油正时控制策略准确地、柔性地控制喷油正时和喷油量.     

基于电喷发动机的挖掘机控制系统设计

现有的机械式发动机排放差、能耗高,采用电喷发动机作为挖掘机的动力源将提高燃油效率,开发电喷发动机的控制系统具有重要意义．在现有挖掘机控制系统的功能分析基础上,确定了基于电喷发动机的控制系统的功能原理图,分析了J1939的协议,确定了电喷发动机的主要参数的解析和控制方法,通过CoDeSys（Controlled Development System）平台设计了电喷发动机的控制系统,并进行了控制试验．试验结果表明：设计的控制系统能正确控制发动机转速和实现相关参数的测量,对挖掘机的电控节能研究具有一定的参考价值．     

Development of a novel rotary flow control valve with an electronic actuator and a pressure compensator valve for a gas turbine engine fuel control system

This paper presents a new rotary proportional flow control valve with Cam-Nozzle configuration. The rotating cam against the fixed nozzle changes the flow area and then can meter the fuel flow. This valve equipped with a pressure compensator plunger type valve to retaining constant pressure difference across the flow control or metering valve. The cam shaft directly coupled to an electronic servomotor type rotary actuator and then it is possible to apply digital control techniques such as pulse width modulation (PWM) in this control system. This new valve configuration is developed for an electro hydro mechanical fuel control system in a gas turbine engine. In addition to aero engine application, this type of flow metering valve can widely be used in industrial hydraulic systems. In this unit, the output flow is proportional to the cam's angular position (or throttle command) and it is not sensitive to pressure fluctuations at nozzle inlet and outlet. The aim of this new design is to modify a manual single adjusted hydro-pneumatic fuel control unit to obtain a new electro-hydraulic fuel control system for a gas turbine engine. The main innovations in the presented fuel metering unit include new design of the rotary valve opening shape (Cam-Nozzle) without metal to metal contact, use of a rotary electronic actuating mechanism and also direct coupling between the actuator and the rotating cam. The increased fuel metering precision in the new flow control valve has improved the ultimate control accuracy of system. A computer simulation software based on the proposed model, is performed to predict the steady state and transient performance and to analyze effect of important design parameters on valve outlet fuel flow and obtain the final design parameters. The validity of the proposed valve configuration is assessed experimentally in the steady state and transient modes of operation. The results show good agreement between simulation and experimental in both modes (max. 4% deviation).     

某柴油机进气歧管优化设计分析

在柴油机的开发过程中,需要评估其进气歧管结构是否能够满足进气均匀性的评价标准。利用CFD软件,通过对某柴油机进气歧管进行稳态分析。计算得到各缸的质量流量、流量系数及流量系数差异性。结果表明:初始方案模型的流量系数差异性不满足评价标准,通过压力分布图找出压力损失部位,对其进行优化;优化方案模型经分析,其结果满足评价标准;在进气歧管的设计开发阶段,通过CFD分析,对进气歧管结构进行优化设计,可以大大减小进气歧管开发的周期、降低成本。     

基于模型的共轨柴油机主喷油量控制算法研究

针对目前高压共轨柴油机电控系统开发周期较长以及开发成本较高的问题,通过研究基于模型的软件开发流程,在Matlab/Simulink环境下建立了高压共轨柴油机主喷油量控制算法模型,其中包括烟度限值控制模型、启动油量控制模型、怠速油量控制模型、怠速PID控制模型以及油量脉宽转换模型;对控制算法模型的关键MAP图进行了标定以验证该控制算法模型的有效性,并在使用INCA标定软件建立监控和标定的发动机试验台架上进行了一系列试验。试验结果表明,发动机启动过程迅速,且正常工况下转速稳定,并能根据环境情况和发动机的当前需求自动调节目标油量;该控制算法能够较好地满足发动机起动、怠速以及正常工况的控制需求。     

某柴油发动机启动异响优化分析

市场反馈某柴油发动机在转速750 r/min附近,一档爬坡过程中产生异响,一档带空调起步及二档带空调起步均存在异响,起步后异响消失。经过初步故障诊断,确定为前端轮系的皮带打滑异响,皮带打滑异响与皮带、张紧器有密切的关系。经过对皮带刚度及强度、底胶工艺、张紧器阻尼的进一步分析,确认上述因素为产生皮带打滑异响的根本原因。在采取皮带和张紧器的整改方案后,完成400小时交变试验验证,验证效果良好。     

故障树分析法在16V280柴油机燃油系统故障诊断中的应用

16V280柴油机在国内内燃机车上应用非常广泛,每年的故障维修量比较大。燃油系统是机车柴油机的五大系统之一。判断故障产生的位置和原因是直接影响维修速度的根本所在。通过故障树分析法对燃油系统进行故障诊断,力求摆脱经验维修和缩短维修时间。     

电控单体泵循环喷油量测量方法及分析

基于先进的 EFS 瞬时喷油量测量仪,采用位移法分别对电控单体泵不同转速工况进行循环喷油量的精确测量。依据循环喷油量及喷油压力的试验数据,得到了电控单体泵喷油量不一致性变化规律以及不同转速下的主要影响因素。分析结果表明,在最大扭矩工况,各单体泵循环喷油量不一致性最低,而启动工况和最大功率工况的不一致性较高。     

Correlation analysis of factors influencing the electronic unit pump cycle fuel injection quantity under overall operating conditions for diesel engines

Electronic unit pump (EUP) can satisfy both diesel engine emission legislation and fuel economy by improving injection pressure and numerical control. Fluctuations in cycle fuel injection quantity (CFIQ) of EUP determine the coherence and stability of the EUP fuel injection system. The EUP simulation model is developed in the AMESim environment. The method for the simulation experiment is designed in the MODDE environment using the design of experiments method. The results of the simulation reveal the variation laws of correlation between parameters with interaction or no interaction under overall operating conditions of diesel engines. In addition, the results also show the EUP system is a complex nonlinear system. Under overall operating conditions, all the characteristic parameters, such as fuel supply pressure, cam profile velocity, control valve lift, injector opening pressure, injector needle lift, and injector flow coefficient, have significant correlation with CFIQ. The interacting first-order factors exhibit the most significant correlation with CFIQ. The self-interacting second-order factors have significant secondary correlation with CFIQ.     

Analysis upon fuel injection quantity variation of common rail system for diesel engines

Fuel injection quantity variation of common rail system has effect on the stability and reliability of diesel engines. For purpose of investigating the influence rule and mechanism of fuel injection quantity variation caused by parameters, taking account of the influence of fuel physical properties on dynamic injection characteristics of the system, a bond graph model of common rail injector has been proposed based on bond graph methodology and the state equations of the system are obtained. Comparisons between calculated fuel injection quantities by the numerical model and experimental measurements at different rail pressures and injection pulse widths indicate that the developed model can reasonably predict the fuel injection quantity characteristic of the system. Fuel injection quantity variation characteristics caused by the parameters of common rail injector have been analyzed in entire operating conditions. The selected parameters are delivery chamber diameter, needle seat semi-angle, needle cone semi-angle, ball valve seat semi-angle, nozzle hole diameter, inlet orifice diameter and outlet orifice diameter. The variation rules of quantitative percentages are obtained by quantitative analysis upon fuel injection quantity variation influential factors. It is concluded that ball valve seat semi-angle, nozzle hole diameter, inlet orifice diameter and outlet orifice diameter have the most significant effect on fuel injection quantity variation, and the followed are delivery chamber diameter and needle seat semi-angle. In addition, needle cone semi-angle also results in the variation of fuel injection quantity, but the effect is insignificant.

     

复杂发动机关键机构的公差分析和优化

分析了公差对复杂发动机性能的影响,提出了针对复杂产品的公差分析和优化方法,综合考虑了各零件公差值大小、公差分布位置和零件误差积累对产品性能的影响,并根据公差分析结果和零件的加工成本等综合因素对零件公差进行优化。定义了具有公差信息的3维模型,开发了通用计算机辅助设计模型到公差模型的数据接口,给出了复杂产品公差分析和公差优化的一般步骤。最后,使用该方法对某型发动机曲柄连杆机构和活塞机构进行了公差分析和优化,并在实际产品开发中得到了验证。     

A study on the design of electromagnetic valve actuator for VVT engine

Electromagnetic valve (EMV) actuation system is a new technology for improving fuel efficiency and at the same time reducing emissions in internal combustion engines. It can provide more flexibility in valve event control compared with conventional variable valve actuation devices. The electromagnetic valve actuator must be designed by taking the operating conditions and engine geometry limits of the internal combustion engine into account. To help develop a simple design method, this paper presents a procedure for determine the basic design parameters and dimensions of the actuator from the relations of the valve dynamics, electromagnetic circuit and thermal loading condition based on the lumped method. To verify the accuracy of the lumped method analysis, experimental study is also carried out on a prototype actuator. It is found that there is a relatively good agreement between the experimental data and the results of the proposed design procedure. Through the whole speed range, the actuator maintains proper performances in valve timing and event control.     

CUMMINS柴油发动机电子调速器及控制系统故障诊断

系统介绍CUMMINS柴油发动机电子调速器及控制系统的工作原理、调整方法和故障诊断技术,有利于准确、快速地排除该类机型的故障.     

基于LabVIEW的汽车电控发动机信号采集与分析系统

随着汽车电子技术的发展,对汽车电控发动机各电信号的检测愈发重要.利用虚拟仪器技术及LabVIEW软件开发平台,配以数据采集卡,实现对发动机上各传感器和执行器产生的电信号进行采集与分析.通过试验证明,这种方法能够实时准确地对发动机上各种电信号进行采集、分析及显示.     

Combustion and emissions of the diesel engine using bio-diesel fuel

The combustion and heat release of engines using diesel fuel and bio-diesel fuel have been investigated. The results illustrate that the combustion happens in advance and the ignition delay period is shortened. The initial heat release peak declines a little, the corresponding crankshaft angle changes in advance, and the combustion duration is prolonged. The economic performance and emission features of diesel engines using diesel fuel and bio-diesel fuel are compared. The results also show that the specific fuel consumption of bio-diesel increases by about 12% .The emissions, such as CO, HC, and particulate matter decrease remarkably whereas NO_x increases a little.     

高速电脑绣花机横梁的动态分析与优化设计

针对高速电脑绣花机横梁振动引起的断线率问题以及刺绣产品质量问题,本文应用ANSYS12.0软件对江门某公司生产的高速ZY-EMSD-A920型电脑绣花机的横梁进行了有限元模态分析、有限元谐响应分析,获得了前四阶固有频率和振型以及各测点随频率曲线变化,然后对其横梁进行了模拟优化改进和模型优化动态特性验证,对今后绣花机结构改进和新机型的开发提供了新的参考方向。     

Combustion and emissions of the diesel engine using bio-diesel fuel

The combustion and heat release of engines using diesel fuel and bio-diesel fuel have been investigated. The results illustrate that the combustion happens in advance and the ignition delay period is shortened. The initial heat release peak declines a little, the corresponding crankshaft angle changes in advance, and the combustion duration is prolonged. The economic performance and emission features of diesel engines using diesel fuel and bio-diesel fuel are compared. The results also show that the specific fuel consumption of bio-diesel increases by about 12%. The emissions, such as CO, HC, and particulate matter decrease remarkably whereas NO _x increases a little. __________ Translated from Journal of Jiangsu University (Natural Science Edition), 2006, 27(3): 216–219 [译自: 江苏大学学报(自然科学版)]