电喷发动机怠速不稳故障原因及排除

针对电喷发动机出现怠速不稳故障而又无故障码显示或显示无关故障码的情况,进行故障原因分析,并提出故障的诊断与排除方法。     

电喷发动机疑难故障的排除方法——连载九：怠速运转不良故障的排除

实例1：本田雅阁轿车为何怠速不稳并有经常熄火现象。故障现象：有一辆广州本田雅阁轿车．发动机怠速不稳．且经常熄火，其它工况时则正常。     

电喷发动机怠速不稳故障的原因与诊断及排除

怠速开关不闭合①原因分析。怠速触点断开,ECU便判定发动机处于部分负荷状态。此时,ECU根据空气流量计和曲轴转速信号确定喷油量,而发动机却是在怠速工况下工作,进气量较少,造成混合气过浓,使转速上升。当ECU收到氧传感器反馈的＂混合气过浓＂信号时,减少喷油量,增大怠速控制阀的开度     

AFE型电喷发动机怠速不稳典型案例

桑塔纳轿车采用的AFE型电喷发动机，配备压力型电控系统，由于工作原理不同，它比流量型电控系统的怠速稳定性稍差，因此该机有一个常见的且比较顽固的故障，就是怠速不稳。该故障有多种表现形式：①怠速时转速大幅度跃变，在500～1200r／min之间“游车”；②怠速转速偏高，在1000r／min以上，驱动空调等负载时转速下降至700r／min以下，且易熄火；③怠速时有间歇性的抖动现象。     

富康电喷发动机偶尔加速不畅的原因及排除

一辆富康电喷发动机出现偶尔加速不畅故障，通过对故障现象的仔细研究和模拟，找出故障的原因是进气压力传感器插接件接触不良。     

电喷发动机怠速不稳故障树分析

应用故障树分析方法,对电喷发动机怠速不稳故障进行分析;给出引起怠速不稳故障的各种原因及其组合方式,进行了故障树的定性分析和定最计算。遵循故障树定性分析所得出的最小割集,可以方便快捷地查找到引起顶事件的底事件故障,为汽车维修人员处理这一典型故障提供分析方法。     

东南车发动机怠速不稳 加速不良

一辆东南DN6473乘用车，装备电控多点喷射四缸发动机。故障现象是：怠速运转时发动机转速不稳，有喘抖现象；冷机加速时，发动机的转速提升迟缓；在行驶中有时故障指示灯亮，油耗超标。     

电喷发动机怠速不良的分析

怠速不良是电子控制汽油喷射发动机最常见的故障之一。它有多种表现形式，如怠速不稳、无怠速、冷车怠速不良、热车速不良、无空调怠速等。造成怠速不良的原因很多，常常是几种原因综合引起。     

电喷发动机怠速不稳故障原因及排除

发动机怠速不稳是汽车常见的故障之一。尽管现在大多数轿车都有故障自诊断系统，但也会出现汽车有故障而自诊断系统却显示正常故障代码或显示与故障无关代码的情况。这通常是由不受电控单元(ECU)直接控制的执行装置发生故障或传统机械故障造成的。下面列举电喷发动机怠速不稳常见的故障原因及其诊断与排除方法。     

Development of an idle speed engine model using in-cylinder pressure data and an idle speed controller for a small capacity port fuel injected SI engine

An idle speed engine model has been proposed and applied for the development of an idle speed controller for a 125 cc two wheeler spark ignition engine. The procedure uses the measured Indicated Mean Effective Pressure (IMEP) at different speeds at a constant fuel rate and throttle position obtained by varying the spark timing. At idling conditions, IMEP corresponds to the friction mean effective pressure. A retardation test was conducted to determine the moment of inertia of the engine. Using these data, a model for simulating the idle speed fluctuations, when there are unknown torque disturbances, was developed. This model was successfully applied to the development of a closed loop idle speed controller based on spark timing. The controller was then implemented on a dSPACE Micro Autobox on the actual engine. The Proportional Derivative Integral (PID) controller parameters obtained from the model were found to match fairly well with the experimental values, indicating the usefulness of the developed idle speed model. Finally, the optimized idle speed control algorithm was embedded in and successfully demonstrated with an in-house built, low cost engine management system (EMS) specifically designed for two-wheeler applications.     

Sensorless adaptive speed control of a permanent-magnet dc motor for anti-lock brake systems

An adaptive control algorithm was developed for the sensorless speed control of a permanent-magnet DC motor directly connected to the hydraulic pump of an antilock brake system. Due to the severe cost and reliability constraints of the application, the motor speed was controlled by a very simple on-off switching method, in which the only measurement required is the voltage across the control switch. The motor speed was calculated solely from the back-EMF voltage during the period of the control cycle when the switching controller is in the switch-off mode. The stability of the developed adaptiveswitching control algorithm was proven mathematically and confirmed experimentally in several vehicle tests over a wide range of target speeds and pump-load conditions. The accuracy and the response time of the controller can easily be tuned by adjusting a single tuning parameter. The switching frequency of the controller can also easily be tuned by adjusting the over-and undershoot thresholds independently from the accuracy of the speed-tracking control.     

Lateral stability control of dynamic steering for dual motor drive high speed tracked vehicle

In this paper, the torque and power required by dual motors for electric tracked vehicle during dynamic steering maneuvers with different steering radiuses are analyzed. A steering coupling drive system composed of a new type of center steering motor, two Electromagnetic (EM) clutches, two planetary gear couplers, and two propulsion motors is proposed for the dual motors drive high speed electric tracked vehicle (2MHETV), which aims to improve its lateral stability. An average torque direct distribution control strategy based on steering coupling and an optimization-distribution-based close-loop control strategy are designed separately to control the driving torque or regenerative braking torque of two propulsion motors for vehicle stability enhancement. Then models of the 2MHETV and the proposed control strategy are established in Recudyn and Matlab/Simulink respectively to evaluate the lateral stability of dynamic steering for the 2MHETV with different steering radiuses on hard pavement.The simulation results show that the lateral stability of the 2MHETV can be significantly improved by the proposed optimization-distribution-based close-loop control strategy based on steering coupling system.     

Boundary conditions of active steering control of independent rotating wheelset based on hub motor and wheel rotating speed difference feedback

The source of torque ripple in a permanent-magnet synchronous motor was analysed. Based on the feedback of the rotating speed difference between the left and right wheels, the error value of torque ripple in an in-wheel motor was calculated. Next, a simulation model of active steering control of an independently rotating wheel (IRW) in an in-wheel motor was developed to investigate effects of torque ripple. The relationship between the accuracy of active steering control of an IRW in an in-wheel motor and wheel/rail profile was derived, and then the boundary conditions of active steering control were obtained. Finally, a method was proposed to improve the active steering control of an IRW by optimising the tread.     

Experimental study of the characteristics of idle vibrations that result from axial forces and the spider positions of constant velocity joints

The vibrational characteristics of automotives during idling were studied experimentally by considering the axial forces of the drive shaft and the spider positions in a constant-velocity joint. The generated forces, such as PF (plunging force) and GAF (generated axial force) in the assembly of the drive-shaft module, were measured directly by an experimental apparatus. Measurements of the GAF and PF did not show the same trends as the joint angles. They depended instead on the types of CV joints. In addition, the relationship between the offset values of the shaft and the spider positions in the tulip of the constant-velocity joint were studied. As a result, the idle vibration characteristics were affected by the variation of the spider positions and the vibrational characteristics in the axial direction of the shaft, including the amplitude and the harmonic periods.     

高速公路车速离散性与交通事故的关系及车速管理研究

对高速公路的车速标准差和亿车公里事故率的数据进行回归分析,建立了二者的关系模型,模型表明车速分布越离散,事故率越高,从而为高速公路的车速限制提供了理论依据。利用中国14条高速公路的地点车速调查数据,对15％位车速、85％位车速与单圆曲线的曲率变化率CCRs进行回归分析,分别建立了85％位车速与CCRs的回归模型以及15％位车速与CCRs的回归模型,利用这些模型提出了合理的基于交通安全的车速限制建议值。     

XMQ6116G混合动力城市客车的开发与设计

混合动力就是指汽车使用汽油驱动和电力驱动2种驱动方式.XMQ6116G混合动力城市客车是厦门金龙公司根据市场需要,联合科研单位及院校研制开发的全新城市客车.本文详细介绍了混合动力汽车的原理及发展方向,并对我公司所生产的XMQ6116G作了重点介绍.     

内练外筑,蓄力发展:玉柴逆市上扬

在全球金融危机不断蔓延的严峻形势下,玉柴却逆水行舟,产品供不应求,订单持续走高:2009年,2月5万多台,3月高达7万多台,第1季度发动机产销双双超过13万台,4月再次突破6万台(这也是玉柴历史上第一次连续2个月突破6万台),同比增长33%,又一次上演了逆市上扬的"玉柴现象".     

试论汽车的功能结构艺术

从营销艺术的角度看，提出概念功能、附加功能、延展功能、特异功能的概念，显然更具有理论和实践意义，不但可以清晰认识汽车功能结构的实质，而且可以准确把握汽车功能结构的规律。有效降低了产品开发的“难度感”，为汽车厂家的产品开发，尤其是汽车功能结构艺术指明了道路。     

改善6130Q型柴油机性能的研究

本文综述了改进6130Q型柴油机性能所采取的措施,对燃烧室和有关系统、零部件进行了大量的改进和试验研究,燃油消耗率、烟度等性能指标明显改善。