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以汽车电控燃油喷射系统基本喷油持续时间的控制为出发点,旨在开发一套汽车电控燃油喷射模拟系统的教学设备。通过进气歧管压力、发动机转速和基本燃油喷射持续时间(喷油脉宽)的测量,得到发动机的喷油脉宽三维脉谱图(MAP),存于单片机ROM中;设计模拟系统硬件电路并对电控单元编程,实时显示传感器检测到的进气歧管压力、发动机转速和喷油脉宽,并控制驱动喷油器工作。 相似文献
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电磁喷油器是轿车发动机电控燃油喷射系统的关键执行元件,它接受电脑送来的喷油脉冲信号,精确地计量燃油喷射量。为了满足现代轿车发动机具有较低的燃油消耗率和较高的功率,各种型号的发动机尽可能使进气空气流量范围扩大,这就要求喷油器具有较宽的动态流量范围并最大限度地利用其动力喷射脉冲。为此,世界各 相似文献
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如何检修汽车喷油器故障 总被引:1,自引:0,他引:1
电控燃油喷射发动机喷油器易发生的问题有:喷油器接线座有油垢脏污,造成接触不良;喷油器针阀粘连,造成喷油器不喷油;喷油器有裂纹、溢油;喷油器其它元件损坏等.检修喷油器的方法如下. 相似文献
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高压共轨燃油喷雾特性的试验研究与模型修正 总被引:3,自引:0,他引:3
利用高速闪光摄像技术建立了燃油喷雾特性试验台架,在不同喷射压力(80 MPa,102 MPa,130 MPa)和不同喷射背压(2 MPa,3 MPa)下对高压共轨电控喷油器的燃油瞬态喷雾特性进行了研究,并用Matlab编程对喷雾图像进行了处理,测量了不同工况下油束的贯穿度和锥角。通过试验数据,利用最小二乘非线性曲线拟合方法对高压喷射油束模型进行了修正,模型计算结果与试验结果基本吻合,表明修正后的油束模型能更好地预测高压喷射时的油束贯穿度和锥角。 相似文献
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驱动参数对GDI压电喷油器特性影响的试验研究 总被引:1,自引:0,他引:1
在油泵试验台上采用不同驱动方式对汽油机缸内直喷(GDI)压电喷油器的流量特性和响应特性进行了研究,测量了喷油器的喷油量、针阀开启时间等参数随驱动电压、电流的变化规律.研究表明:采用单峰值和恒定电流驱动方式,随着驱动电压的增大,喷油量近似呈线性增加,当电压大于155 V时,喷油量保持不变;采用多峰值电流驱动,随着驱动电压的增大,喷油量不断增大.采用恒定电流和多峰值电流驱动时,驱动电流对喷油量的变化影响不大.相同电流时,多峰值电流驱动的喷油量小于恒定电流驱动的喷油量.压电喷油器的响应时间随着驱动电压、驱动电流和电流变化率的增加逐渐减少,并最终趋于稳定. 相似文献
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采用切线凸轮的电控单体泵燃油系统性能研究 总被引:2,自引:0,他引:2
研究了电控单体泵燃油系统特性在匹配切线凸轮型线下的燃油特性。进行了高转速和低转速下的试验,低转速下对应的供油速度低,如果供油提前角太提前将导致断续喷射,高转速下较大的凸轮速度将对应较高的供油速度,使得供油压力高,因此可用凸轮速度范围受到限制,切线凸轮速度变化较大使得对应的工作区间较短;进行了不同提前角下的试验,供油角度的变化对电控单体泵燃油系统喷射特性影响较大,不利于通过调节喷油角度来优化排放性能;进行了不同油量下系统的特性试验,发现不同油量下喷射特性变化大,变化规律不满足理想喷油规律的需求;进行了高速下燃油系统试验,高速时由于压力波的影响出现了二次喷射。结果说明,切线凸轮型线的速度段斜率大,能够快速实现高速供油,有利于快速建立供油压力,但是采用切线凸轮的单体泵燃油系统的供油特性受到转速和提前角的影响,不利于发动机面工况的匹配和大功率柴油机的需求。 相似文献
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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. 相似文献
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《JSAE Review》1998,19(3):217-222
A direct-injection stratified charge gasoline engine has been developed that can run on an air–fuel ratio of 40–50 : 1. Major characteristics of the engine system include swirl gas flow and fuel injection in a swirl spray at a maximum fuel pressure of 10 MPa. Another notable feature is that the intake port configuration is virtually identical to that of a conventional engine, allowing flexibility for shared use of components among different engines. This new engine achieves better fuel economy, lower cold-start HC emissions and higher power output than conventional multipoint injection engines. 相似文献
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简介不同的电喷发动机燃油泵和喷油器的控制电路原理。并分别介绍喷油器的几种喷油方式以及喷油器的驱动方式和特点。 相似文献
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《JSAE Review》1996,17(1):3-9
A fuel injection simulation code was developed with an approximate lumped-parameter network scheme. This code has many improvements for obtaining better computational accuracy. These include a new iteration approach, a nonuniform dividing method of injection pipe, a large number of injection system elements and consideration of kinematic viscosity of the fuel and its flow resistance through the injector during the throttling period. This simulation code was used to evaluate various control systems of injection rate for IDI diesel engines. Based on the results, a comparison was carried out among control characteristics of fuel injection rate of these systems, and clear correlation was shown between operating conditions of the injection pump and injection rates. 相似文献
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