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为了研究不同供油压力下单体泵的建压过程及单体泵性能呈现出的变化规律,在电控单体泵试验台上进行了油泵台架试验,获得了高转速工况下不同供油压力的单体泵油压特性曲线。分析了供油压力与单体泵喷油压力之间的关系,并研究了电控单体泵空转时供油压力对单体泵性能的影响。结果表明:高转速时,供油压力低,油压建立过程存在无规律波动;高转速时,一定范围内,供油压力越大,油压上升时刻越早;不同转速对应着不同的临界充油压力,当供油压力大于等于临界压力时,单体泵才能够稳定而有规律地建压;相同工况下,一定范围内,供油压力越大,单体泵喷油量越大。 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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道依茨(DEUTZ)柴油发动机EDC16电控单体泵系统(以下简称EDC16系统)是一个新型的全电子控制柴油机燃油喷射系统,它不再采用机械调速器(没有齿杆装置),与传统的机械喷射系统不同的是:EDC16系统采用转矩控制策略,可以自由控制发动机输出转矩(喷油量)和喷油开始时间(喷油定时)。电控单体泵供油系统的喷油泵是单体的, 相似文献
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起动困难或者无法起动是柴油机的常见故障现象,造成故障的原因包括发动机机械性能、燃油供应及环境温度等,对于国Ⅲ电控柴油机,电控系统工作是否正常对起动性能也有很大的影响。玉柴YC4D130-30电控柴油机装配国产的南岳衡阳电控单体组合泵系统(以下简称衡阳单体泵),该系统属于第2代时间控制式电控柴油喷射系统。电控单体组合泵系统为外挂的单体泵方式,将单体 相似文献
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This paper presents an accurate engine fuel injection quantity control technique for high pressure common rail (HPCR) injection
systems by an iterative learning control (ILC)-based, on-line calibration method. Accurate fuel injection quantity control
is of importance in improving engine combustion efficiency and reducing engine-out emissions. Current Diesel engine fuel injection
quantity control algorithms are either based on pre-calibrated tables or injector models, which may not adequately handle
the effects of disturbances from fuel pressure oscillation in HPCR, rail pressure sensor reading inaccuracy, and the injector
aging on injection quantity control. In this paper, by using an exhaust oxygen fraction dynamic model, an on-line parameter
calibration method for accurate fuel injection quantity control was developed based on an enhanced iterative learning control
(EILC) technique in conjunction with HPCR injection system. A high-fidelity, GT-Power engine model, with parametric uncertainties
and measurement disturbances, was utilized to validate such a methodology. Through simulations at different engine operating
conditions, the effectiveness of the proposed method in rejecting the effects of uncertainties and disturbance on fuel injection
quantity control was demonstrated. 相似文献
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在CA7220型红旗轿车上应用多点电子喷射系统,提高了整车的动力性、经济性,降低了排放。重点介绍了电子燃油喷射系统的控制功能和工作流程,空燃比和点火角最佳控制参数的匹配,并给出了装用化油器和装用多点喷射系统的整车性能对比曲线。 相似文献
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Y. Bai L. Y. Fan X. Z. Ma H. L. Peng E. Z. Song 《International Journal of Automotive Technology》2016,17(4):567-579
In this paper, the bond graph model of common rail injector was proposed in consideration of the effects of variable liquid capacitance and fuel physical property on the injection characteristics of the injector. State equations were derived based on the model, which were numerically solved by programming in Matlab. Comparisons between the simulation results and the experimental data show that the numerical model can effectively predict the injection quantity of the system. Effect of variation of 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 on fuel injection quantity had been analyzed. The influence rules of various parameters on the fuel injection quantity had been established. The experiments were conducted using face centered central composite design. A second order polynomial response surface model had been developed for predicting fuel injection quantity, as a function of the independent variables. Analysis of variation was used to determine the significance interactions which primarily affect the fuel injection quantity. It had been concluded that six interaction factors including delivery chamber diameter with nozzle hole diameter, needle seat semi-angle with needle cone semi-angle, needle seat semi-angle with nozzle hole diameter, needle cone semi-angle with nozzle hole diameter, nozzle hole diameter with inlet orifice diameter, and nozzle hole diameter with outlet orifice diameter have significant effect on the fuel injection quantity of the system. 相似文献
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U. Egüz N. C. J. Maes C. A. J. Leermakers L. M. T. Somers L. P. H. De Goey 《International Journal of Automotive Technology》2013,14(5):693-699
The objective of new combustion concepts is to meet emission standards by improving fuel air mixing prior to ignition. Since there is no overlap between injection and ignition, combustion is governed mainly by chemical kinetics and it is challenging to control the phasing of ignition. Reactivity Controlled Compression Ignition (RCCI) combustion aims to control combustion phasing by altering the fuel ratios of the high- and low octane fuel and injection timings. In this study the dual fuel blend is prepared with gasoline and diesel fuels. The applied injection timings of the diesel are very early (90 to 60° CA bTDC). In the detailed reaction mechanism, n-heptane and iso-octane represent diesel and gasoline fuel, respectively. A multi-zone model approach is implemented to perform RCCI combustion simulation. Ignition characteristics are analyzed by using CA50 as the main parameter. In the experiments for the early direct injection (DI) timing advancing the injection time results in a later ignition. Qualitatively, the trend effect of the diesel injection timing and the effect of the ratio gasoline/diesel are captured accurately by the multi-zone model. 相似文献
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改善火花助然甲醇发动机小负荷经济性的研究 总被引:4,自引:0,他引:4
小负荷时经济性差,是火花助燃甲醇发动机存在的主要问题。以1130立式水冷直喷柴油单缸机为对象,研究了点火系统、压缩比、喷油嘴油线分布和喷油嘴针阀开启压力等因素对火花助燃甲醇发动机小负荷时经济性的影响,并将之与柴油发动机进行了对比分析。 相似文献
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论述了发动机电控汽油喷射系统的发展概况及其分类方法,并对其进气系统、燃油供给系统和电子控制系统构件的结构和工作原理进行了详细介绍。提出了5种检测电控汽油喷射系统故障的方法,并以丰田汽车公司皇冠3.O轿车用2JZ-GE型发动机的电控汽油喷射系统为对象,介绍了用万用表检测技术参数法对其进行检修的步骤和方法。 相似文献