GJ85型链锯的电容放电式无触点磁电机

本文拟重点介绍“GJ85”电容放电式无触点磁电机充电电路的特点、可控硅的选用、触发线圈和点火线圈的特点等,以期得到有关同志们的指教,共同推动电容放电式无触点磁电机的设计研究工作向前发展。     

脉冲爆震发动机起爆点火系统方案研究

在分析爆震波的基本理论、脉冲爆震发动机(PDE)的工作原理及对现有航空发动机和汽车点火系统进行研究的基础上,根据PDE对起爆系统点火能量和火花频率可调的要求,提出了以晶闸管为开关控制元件和电容储能的半导体高能点火系统方案．设计的倍压整流、半波整流和直流供电的脉冲爆震发动机起爆点火系统实现了点火能量和火花放电频率的控制．电路模拟仿真表明,设计的起爆点火系统可满足脉冲爆震发动机的要求．     

190F汽油机无触点磁控管点火系统

介绍190F汽油机无触点磁控管点火系统（简称MI）的结构特点、工作原理，并与目前广泛使用的无触点电容放电式点火系统（简称CDI）进行比较。     

基于MC68HC908单片机的数字点火系统的设计与实现

本文以MC68HC908JK3芯片为核心设计了一种二冲程发动机数字点火系统(DCI),解决了电容放电点火(CDI)系统低速断火和高速失火问题,并且具有降低油耗的功能。     

基于MC68HC908单片机的数字点火系统的设计与实现

本文以MC68HC908JK3芯片为核心设计了一种二冲程发动机数字点火系统（DCI），解决了电容放电点火（CDI）系统低速断火和高速失火问题，并且具有降低油耗的功能。     

大型煤气机多次放电点火系统

上图为多次放电(CIMD)的 Pulstronic1000简化电路,说明如何经过简单的改接,作为多火花的组件也可以获得单次放电。有 CIMD 线路的 Pulstronic 1000点火系统有一个自备的发电机,被设计成带变压器的完全对称的电容放电点火系统。只要拆去一根连线就可以由多次放电装置 CIMD 变成单次放电点火。为了用最高的效率和最低的能量去获得希望的火花特性,转换为高压火花塞能量的     

四冲程汽油机点火装置的设计与实现

本文以四冲程汽油发动机为基础,该发动机采用了双凸轮轴的磁电机转子设计。针对该磁电机转子的特点,设计采样和点火电路,结合点火补偿策略设计并实现一套新的发动机点火系统。单片机实时读取速度和节气门开度信号,并通过对发动机功率曲线的测量绘制发动机点火提前角的MAP图。整机测试结果显示,该系统提高了摩托车的点火提前角的控制精度和点火能量,提高了发动机的输出功率和转拒。     

电容放电式点火系统的优化设计

本文分析了摩托车用的电容放电式点火系统的工作原理,建立了电容充电线圈与储电电容关系的数学模型,为电容放电式点火系统的设计提供了理论依据。     

采用三极管开关电路的无触点磁电机

我厂生产的可控硅电容放电式无触点磁电机,配套使用在小型高速汽油机上。最近,我们参考西德“STIHL O3AV electronic”链锯汽油机的点火装置,采用半导体三极管开关电路,试制成功了新型的无触点磁电机。其结构见图1、电路见图2。     

《小型内燃机》1971～1974年各期主要内容

1 971。1美国小型汽油机概况日本通用汽油机概况国外几种小型转子发动机小型发动机经济的固态点火固态电容放电电火系统关于无触点电容放电点火设计的一些考虑小型发动机无触点点火和点火发电装置电子式燃油喷射装置美国几种工业用小型汽油机防干扰的火花塞和一导线汽化器的作用磁电机燃料和燃烧特性层状给气发动机的燃烧层状给气在小型汽油机上的试验国外三角活塞旋转发动机缸体与刮片的配对情 况 n向s/D对发动机零件动负荷的影响按包络线画出转子发动机的型线风冷发动机的发展对置活塞旋转发动机内燃机用新型铝合金1972。11 971。2了O系…     

一种可控火花能量的交流点火系统研究

基于电容储能式电控点火系统研究了一种火花持续期、次级火花电流可控的交流点火系统。利用CADENCE PSPICE软件以及模拟负载试验,验证了不同斩波电流、驱动脉宽等可变参数对交流点火系统火花能量的影响。试验结果表明:火花能量的提高依赖于斩波电流值的增大和驱动脉宽的延长,并近似呈线性关系;交流点火系统火花持续时间可实现2.5 ms内可控调节,初级斩波电流可实现30 A内可控调节。交流点火系统可通过相应参数的调节实现火花能量可控,最大火花能量可达到260 mJ,满足气体燃料发动机的功能需求。     

Experimental study of ignition of magnesium powder by electrostatic discharge

Ignition of non-aerosolized powders by electrostatic discharge (ESD) is investigated. A spherical powder of Mg, for which thermal ignition kinetics was described in the literature, was used in experiments. The experimental setup was built based on a commercially available apparatus for ESD ignition sensitivity testing. Additional diagnostics enabled measurements of electrical current, voltage, and spark and ignited powder emission in real time. The spark duration was of the order of a few μs. The spark current and voltage were always observed to have significant AC components. The electrical impedance of the spark discharge was determined experimentally using the recorded current traces and assuming that the spark and powder could be represented as a series LRC circuit. The optical emission was filtered to separate the signals produced by the spark plasma and by the heated and igniting powder. The radiation signal produced by the igniting powder was always delayed after the spark. The delay time decreased from about 3.5 to 0.5 ms as the spark energy increased from 10 to 60 mJ; the delay remained nearly constant when the spark energy continued to increase to over 100 mJ. For experiments where the powder volume decreased or where binder was introduced delay times were reduced. For the powder with a small amount of binder, the ignition delay continued to decrease for spark energies exceeding 60 mJ. Interpretation of the obtained experimental data suggests that the ignition is primarily due to direct Joule heating of the powder by the spark current.     

Advancing lean combustion of hydrogen-air mixtures by laser-induced spark ignition

We investigate how ignition through laser-induced plasma can improve the application of lean combustion, in particular in environmental conditions relevant to hydrogen internal combustion engines (ICE). Major design goals when developing combustion engines are increasing thermal efficiency and decreasing combustion emissions. High compression ratios, lean combustion and precise ignition timings are contributing factors in ICE optimization. In our studies, several gains from laser spark ignition are investigated. The high energy content of laser-induced ignition kernels are shown to speed up the development of the early flame kernels. These extended ignition kernels transfer into self propagating flames even in lean mixtures. Leaner mixtures are ignited in our experiments using laser spark ignition in comparison to conventional electrical spark plugs. Precise ignition timing is realized. Multi-point ignitions are synchronized on the timescale of microseconds to enhance the progress of combustion. We modified the locus of ignition in a mixture flow to decrease the temporal extent of flame contact with the wall. Therefore, burning duration and heat loss can be reduced.     

点燃式发动机点火能量对火核生成和初期发展的影响

摘要本文研究了点燃式发动机点火能量对火核生成和初期发展的影响.发现增加点火时的击穿能量,可使火核的初始尺寸有效地增加,从而加快火焰的形成和初期发展,并且可以燃烧更为稀薄的混合气,而仅仅增加电容和电感放电阶段的点火能量却没有显著的效果.     

SI燃烧过程优化途径的试验和仿真研究

在快速压缩-膨胀机上通过试验和仿真手段,研究了火花塞数目、活塞运动规律、压缩比对单次循环指示功和爆震倾向的影响。研究表明:使用多火花塞点火能缩短燃烧持续期和提高指示功,但是爆震倾向明显增加;提高活塞运动速度,减少活塞在上止点附近的停留时间,可以减少爆震倾向,但是相同条件下指示功有所降低;综合使用多火花塞点火,提高活塞运行速度和采用高达17.5的压缩比,可以提高指示功并抑制爆震,使SI燃烧过程得到优化。     

Statistical analysis of electrostatic spark ignition of lean H2/O2/Ar mixtures

The concept of minimum ignition energy (MIE) has traditionally formed the basis for studying ignition hazards of fuels. However, the viewpoint of ignition as a statistical phenomenon appears to be more consistent with the inherent variability in engineering test data. We have developed a very low-energy capacitive spark ignition system to produce short sparks with fixed lengths of 1-2 mm, and the ignition system is used to perform spark ignition tests using a range of spark energies in lean hydrogen-oxygen-argon test mixtures used in aviation safety testing. The test results are analyzed using statistical tools to obtain probability distributions for ignition versus spark energy. A second low-energy spark ignition system was also developed to generate longer sparks with varying lengths up to 10 mm. A second set of ignition tests is performed in one of the test mixtures using a range of spark energies and spark lengths. The results are analyzed to obtain a probability distribution for ignition versus the spark energy per unit spark length. Preliminary results show that a single threshold MIE value does not exist, but rather that ignition is statistical in nature and highly dependent on mixture composition and spark length.     

Measurements of minimum ignition energy in premixed laminar methane/air flow by using laser induced spark

Reducing engine pollutant emissions and fuel consumption is an important challenge. Lean-burning engines are a promising development; however, such engines require high-energy ignition systems for typical working conditions (equivalence ratio, Φ < 0.7). Laser-induced ignition is envisaged as a way to obtain high-energy ignition as a result of progress that has been made in laser beam technology in terms of stability, size, and energy. This study investigated the minimum energy necessary to ignite a laminar premixed methane air mixture experimentally. A parametrical study was performed to characterize the effects of the flow velocity, equivalence ratio, and lens focal length on the minimum energy required for ignition. Experiments were conducted using a premixed laminar CH₄/air burner. Laser-induced breakdown was achieved by focusing a 532-nm nanosecond pulse from a Q-switched Nd:YAG laser with an anti-reflection-coated lens. Mixture ignition and the early stages of flame propagation were studied using a high speed Schlieren technique. Despite the stochastic characteristic of the laser breakdown phenomena, good reproducibility in the minimum energy required for the ignition measurements was observed. The cases in which the CH₄/Air mixture flow ignites are defined as those with a laminar flame front propagation visible in the Schlieren images 10 ms after the energy deposition. The same minimum ignition energy (MIE) versus equivalence ratio (Φ) type of curves were obtained with a laser-induced spark and with a spark plug. Due to the threshold of energy required to obtain breakdown and the stochastic character of the energy absorption by the spark, a constant value was obtained (corresponding to the breakdown threshold) when the minimum ignition energy was lower than the breakdown threshold. As already noticed by several authors, MIE values higher than those observed using spark plugs were obtained. However, these differences tended to disappear at the lean and rich fuel limits.     

A multi-mode combustion diagram for spark assisted compression ignition

The potential utility of spark discharges to assist low temperature, compression ignited engines has resulted in a number of experimental studies. These show mixed results; sometimes spark is effective at controlling heat release timing, sometimes it only stabilizes combustion, and sometimes it has no effect at all. In order to help understand the spark assisted process we propose a multi-mode combustion diagram to delineate the regimes of spark ignition, flame propagation, compression ignition, knocking combustion and spark-assisted combustion, in terms of unburned and burned gas temperatures near top dead center. An analysis of existing experimental data suggests that the effectiveness of spark assist is best at higher and middle loads and decreases as load is reduced.     

火花点火式煤层气发动机的燃烧过程实验研究

对由S195柴油机改装得到的燃用变组分煤层气发动机进行了全面的测试和分析，包括缸内示功图、燃烧放热率、主燃期、点火提前角、火焰发展期以及最大压力循环波动等。结果表明：甲烷浓度、点火提前角、负荷的大小对火焰发展期、循环波动以及燃烧有着至关重要的影响。