自动变速器车辆发动机制动工作条件与诊断分析

发动机制动是车辆减速的一种有效方式,拥有很多优点。对于手动变速器车辆,车辆行驶时,发动机与驱动轮之间近似为刚性联接,所以容易实现发动机制动;但对于自动变速器车辆,发动机制动实现起来却复杂得多。基于NISSAN TEANA采用的RE4F04B自动变速器,详细分析了发动机制动的工作条件与故障诊断步骤。     

自动变速器使用注意事项

发动机起动时换挡杆位置要正确装有自动变速器的汽车均设有安全机构联锁开关。车辆处于停车状态下起动时，必须拉紧驻车制动手柄，并把换挡杆放到停车挡P的位置，然后踩下制动踏板，方可打开点火开关，待发动机起动预热后，才可起步行车。这一点与手动变速器是有明显区别的，这主要是由于自动变速器安全机构联锁开关的控制作用所致。倘若起动发动机时，自动变速器换挡杆不在停车挡P位置，空挡起动开关将会自动切断起动电路，使发动机无法起动，从而确保发动机起动和汽车起步时的车辆、人员安全。     

自动变速器行星齿轮系统的快速分析方法

分析自动变速器行星齿轮系统工作原理的两个关键点是：1）车辆加速时各档传动的实现；2）车辆滑行时对发动机制动的控制。     

保时捷自动起停功能失效故障诊断与排除

<正>1自动起停系统简述配备保时捷双离合器变速器的PANAMERA(帕兰美拉)采用了一种自动起动/停止功能。该功能可在车辆允许停车的规定条件下关闭发动机,有助于降低停车时的油耗、噪声和排放,避免无谓怠速(如在停车等红绿灯时)。该功能在发动机和变速器达到工作温度即可使用。可以通过挂档杆旁边的自动起停开关(图1)来实现开启和关闭功能。自动起停系统控制原理如图2所示。如果车辆通过制动停车后继续踩住制动踏板,约     

2005款帕萨特(1.8T)自动制动的奇特故障

故障现象:行驶时车辆左前部有异响。故障诊断:这辆车本来是因自动变速器故障进厂维修的,路试时听到车辆左前部有响声,声音从制动分泵处传出来的,但此时驾驶员并没有踩制动踏板。开始怀疑是制动分泵发卡引起的,把车辆用举升机顶起来,启动发动机,用手转动左前轮能自由转动,但转到一定转速时,车轮即自动抱死。很明显是ABS     

2015款雪佛兰赛欧3新技术剖析(四)

<正>当车辆在手动模式下行驶时,通过+挡/-挡来实现变速器挡位升降。换挡要求不合理时,换挡命令无效且警报声会响起。如果车辆加速或减速行驶,当发动机转速升高或下降到一定转速后,变速器会自动升挡或降挡。当车辆在自动模式下行驶时,仅通过加速踏板和制动踏板来控制车辆的行驶,系统自动实现合适的挡位切换。当急踩加速踏板至节气门全开或接近于全开时,系统有可能会降1~3个挡位。变速器换挡控制单元为总成件,     

自动变速器错误使用六例

一、自动变速器车辆长时间停车时，换档杆仍挂在D档 装备自动变速器的车辆在等待通过信号或堵车时。一些驾驶员常将换档杆保持在D档，同时踩下制动踏板，若时间很短，这样做是允许的。但若停车时间长最好换人N档（空档），并拉紧驻车制动。因为换档杆在D档时，自动变速器汽车一般有微弱的前移，若长时间踩住制动踏板。等于强行制止这种前移，使得变速器油温升高，油液容易变质，尤其在空调系统工作时，发动机怠速较高的情况下更为不利。     

电控机械式自动变速器制动装置研究

为实现电控机械式自动变速器（AMT）在升挡过程中对发动机以及变速器1轴的减速,使变速器目标挡位齿轮与输出轴同步最终实现换挡,文章设计了一种安装于变速器上的气动制动器。通过对变速器中间轴进行制动,实现减速升挡。安装试验结果表明,该气动制动器满足了在升挡过程中对发动机以及变速器1轴的减速要求。该制动装置具有结构简单及响应快速的特点,有效提高了换挡品质。     

奥迪A6L间歇性无法起动

正一、故障现象有一辆2014款奥迪A6L轿车,配备2.0T发动机,0AW变速器,行驶里程2.9万km。客户反应车辆行驶中遇红灯停车踩住制动踏板,发动机起停功能起作用,车辆自动熄火。绿灯后,松开制动,正常发动机应立即起动,但只听到起动机连续的起动声,车辆无法着车。连续起动多次,有时能着车。二、故障诊断     

三星太空车制动时熄火,不制动时车辆行驶

一辆三星太空车(配用F4A23自动变速器)在D、R位时，踩制动踏板时发动机熄火；不踩制动踏板时，即便不踩加速踏板车辆也向前或向后移动。     

在变速器上安装发动机减速装置的研究

电控机械式自动变速器是一种目前主流的商用车自动变速器,已成为各失主机厂和独立变速器厂的研究重点。而在换挡过程中对发动机进行减速控制又是其中一项关键技术。文章首先介绍了发动机减速常采用的方法,提出了在变速器上安装发动机减速装置的2种方法。通过分析,选用电磁离合器作为减速装置的核心部件,提出了一种适用于重型车AMT的发动机减速器方案。     

Heavy-duty vehicle modelling and longitudinal control

This paper addresses modelling, longitudinal control design and implementation for heavy-duty vehicles (HDVs). The challenging problems here are: (a) an HDV is mass dominant with low power to mass ratio; (b) They possess large actuator delay and actuator saturation. To reduce model mismatch, it is necessary to obtain a nonlinear model which is as simple as the control design method can handle and as complicated as necessary to capture the intrinsic vehicle dynamics. A second order nonlinear vehicle body dynamical model is adopted, which is feedback linearizable. Beside the vehicle dynamics, other main dynamical components along the power-train and drive-train are also modelled, which include turbocharged diesel engine, torque converter, transmission, transmission retarder, pneumatic brake and tyre. The braking system is the most challenging part for control design, which contains three parts: Jake (engine compression) brake, air brake and transmission retarder. The modelling for each is provided. The use of engine braking effect is new complementary to Jake (compression) brake for longitudinal control, which is united with Jake brake in modelling. The control structure can be divided into upper level and lower level. Upper level control uses sliding mode control to generate the desired torque from the desired vehicle acceleration. Lower level control is divided into two branches: (a) engine control: from positive desired torque to desired fuel rate (engine control) using a static engine mapping which basically captures the intrinsic dynamic performance of the turbo-charged diesel engine; (b) brake control: from desired negative torque to generate Jake brake cylinder number to be activated and ON/OFF time periods, applied pneumatic brake pressure and applied voltage of transmission retarder. Test results are also reported.     

Heavy-duty vehicle modelling and longitudinal control

This paper addresses modelling, longitudinal control design and implementation for heavy-duty vehicles (HDVs). The challenging problems here are: (a) an HDV is mass dominant with low power to mass ratio; (b) They possess large actuator delay and actuator saturation. To reduce model mismatch, it is necessary to obtain a nonlinear model which is as simple as the control design method can handle and as complicated as necessary to capture the intrinsic vehicle dynamics. A second order nonlinear vehicle body dynamical model is adopted, which is feedback linearizable. Beside the vehicle dynamics, other main dynamical components along the power-train and drive-train are also modelled, which include turbocharged diesel engine, torque converter, transmission, transmission retarder, pneumatic brake and tyre. The braking system is the most challenging part for control design, which contains three parts: Jake (engine compression) brake, air brake and transmission retarder. The modelling for each is provided. The use of engine braking effect is new complementary to Jake (compression) brake for longitudinal control, which is united with Jake brake in modelling. The control structure can be divided into upper level and lower level. Upper level control uses sliding mode control to generate the desired torque from the desired vehicle acceleration. Lower level control is divided into two branches: (a) engine control: from positive desired torque to desired fuel rate (engine control) using a static engine mapping which basically captures the intrinsic dynamic performance of the turbo-charged diesel engine; (b) brake control: from desired negative torque to generate Jake brake cylinder number to be activated and ON/OFF time periods, applied pneumatic brake pressure and applied voltage of transmission retarder. Test results are also reported.     

现代汽车的自动变速器技术及应用

自动变速器是现代汽车上一个重要的动力传递总成,对提高汽车的动力性和驾驶舒适性具有重要作用。文章介绍了目前汽车上应用的电控机械式自动变速器（AMT）、液力机械自动变速器（AT）、无级自动变速器（CVT）及双离合自动变速器（DCT）,指出AMT适用于商用车和公交车,AT将大量应用于6挡以上的中高级车,CVT适用于排量在3L以下及混合动力车,DCT可广泛应用于各种车型.     

Brake Valve Timing and Fuel Injection: a Unified Engine Torque Actuator for Heavy-Duty Vehicles

A unified engine torque actuator for heavy-duty vehicles is developed in this paper. Based on averaging and identification of the instantaneous torque response for changes in brake valve timing and fuel flow, we derive a control oriented engine model of a six cylinder, 350 Hp turbocharged diesel engine, equipped with a compression brake. This work bridges the gap between the detailed compression crank angle based models developed in the engine design community, and the first order lag representation of diesel engine torque response used in the vehicle dynamics community. Moreover, we integrate the compression brake actuator with the service brakes and design a PI-controller that emulates the driver's actions during long descends on grades. The controller simply uses the engine speed measurement to activate the service brakes only when needed.     

Brake Valve Timing and Fuel Injection: a Unified Engine Torque Actuator for Heavy-Duty Vehicles

A unified engine torque actuator for heavy-duty vehicles is developed in this paper. Based on averaging and identification of the instantaneous torque response for changes in brake valve timing and fuel flow, we derive a control oriented engine model of a six cylinder, 350 Hp turbocharged diesel engine, equipped with a compression brake. This work bridges the gap between the detailed compression crank angle based models developed in the engine design community, and the first order lag representation of diesel engine torque response used in the vehicle dynamics community. Moreover, we integrate the compression brake actuator with the service brakes and design a PI-controller that emulates the driver's actions during long descends on grades. The controller simply uses the engine speed measurement to activate the service brakes only when needed.     

汽车运行材料的应用现状及发展趋势

综述了汽车用燃料(汽油、柴油、代用燃料)、润滑剂(发动机润滑油、齿轮油、自动变速器油、润滑脂)、特种液(制动液、冷却液、空调制冷剂)、燃料添加剂及润滑剂添加剂等运行材料在国内外的应用现状及发展趋势。该研究可为汽车运行材料的新产品研发提供参考。     

Analysis on fuel economy and advanced systems of hybrid vehicles

Basic ideas on operation of hybrid vehicles were discussed from a view point of energy saving. Almost double fuel economy of series–parallel–hybrid vehicles was estimated on condition of no engine idling during vehicle stop, energy saving in acceleration using brake energy recovery and high efficiency operation on low load condition using series–hybrid system. From the discussion of overall efficiency, involving fuel cycle, under both low and high load conditions, both series–parallel–hybrid vehicles with internal combustion engine and fuel cell are supposed to have a high potential for the future.     

油门踏板快速松开时自动变速器换挡控制

针对装备自动变速器的车辆在油门踏板快速松开时的意外换挡问题,通过采集车速、油门和制动信号并结合2参数换挡规律,找到了该车辆意外换挡的原因.对该车TCU换挡控制策略进行了优化.建立整车纵向动力学仿真模型,以实车采集到的油门、制动信号作为模型的输入量进行了仿真试验,并通过实车试验对优化后策略进行了验证.结果表明,优化后策略...