汽车挂车的选型与设计(四)

1.拖挂重量: 汽车列车的牵引车和挂车往往是由不同的厂家生产的,根据牵引车所能拖拽的挂车总重量或汽车列车总重量的名义值,来选择挂车。如拖拽全挂车,挂车总重为全挂车自重加上有效载重量;对于鞍式半挂车。要算出鞍式牵引座(有人称为第五轮)上的垂直载荷,这个载荷     

汽车列车转弯过程的分析及其最小转弯半径的确定

由牵引车带半挂车组成的汽车列车的转弯过程与单车的转弯过程有所不同,本文的目的是对这种汽车列车的转弯过程进行运动分析,并导出计算前外轮最小转弯半径的公式。在转向几何学范畴内对汽车的转弯进行运动分析时,常不考虑因惯性力而引起的侧滑和由于轮胎的弹性所引起的侧向偏离。本文在分析时也是以此为基础的。     

双挂汽车列车操纵稳定性评价指标研究

为了确定双挂汽车操纵稳定性的评价指标并进行横向稳定性分析,在分析国外多挂汽车列车研究现状的基础上,分别总结了结构参数和使用参数以及各种主动控制策略对多挂汽车列车横向稳定性的影响。与中国汽车列车操纵稳定性评价方法相比,针对多挂汽车列车增加了后部放大系数(RWA)和轨迹偏移量(Off-tracking)2种横向稳定性评价指标;构建了横摆运动和侧向运动的双挂汽车列车动力学模型,仿真阶跃响应下各个车辆单元侧向速度、横摆角速度、侧向-横摆相轨迹、侧向加速度以及铰接角的变化,并分别计算以横摆角速度和侧向加速度为基准的RWA值,将计算结果与国外相关研究文献进行了比较。结果表明:当牵引车和一挂车的侧向速度最大值分别为1.15,0.89m·s~(-1)时,对应拖台和二挂车的侧向速度最大值分别为2.81,1.31m·s~(-1),证明其为双挂汽车列车发生失稳的主要影响因素;由横摆角速度、侧向加速度对应的RWA值分别为1.14和1.54可知,以侧向加速度为基准的RWA值更能反映车辆的后部放大状态;由牵引车与一挂车之间的铰接角为5.9°,拖台与二挂车之间的铰接角为9.6°,而一挂车与拖台之间的铰接角恢复到0可知,一挂车与拖台的链接形式比第5轮式的铰接形式更稳定,且恢复到稳定状态时间更短;研究结果可为双挂汽车列车操纵稳定性评价指标的确定及应用提供参考。     

汽车挂车的选型与设计(七)

五、汽车列车的牵引计算汽车列车的牵引计算几乎和汽车的牵引计算是一样的,没有多大差别。如说有不同,那就还要考虑:①汽车拖带挂车后总重增加了,比功率较低;②空气阻力增加了,在近似计算时,每增加一节挂车,空气阻力就增加15～20%;③由于挂车轮距大,有时不能与牵引车同轮迹,还有一些挂车装用了数量较多的轮胎,所以滚动阻力也增大了。     

关于汽车列车制动性能检验方法的理解

<正>根据《机动车安全技术检验项目和方法》(GB 21861-2014)实施以来的实际情况,部分检测站提出如何进行汽车列车(牵引车和挂车)制动性能检验及现有的设备能否进行汽车列车制动性能检验等问题,下面笔者谈谈自己的理解。1 GB 21861-2014中对汽车列车制动性能检测的规定GB 21861-2014中6.8.1.2条款规定,对于全挂车、半挂车,台试空载制动性能检验时,应同时满足以下要求:与牵     

全挂汽车列车主动转向建模分析

汽车列车在公路交通运输中起着举足轻重的作用,为公路货运量流通提供高性价比的运输方式,贴合当代发展需求。随着汽车列车使用需求日益增长,其不足之处也日益凸显,因而提高汽车列车的运输效率及安全性,保证汽车列车长远发展势在必行。现基于一种双杆式全挂汽车列车提出主动转向控制研究方法,使车辆进行弯道行驶时,在主动转向装置和主动转向控制方法的双重作用下实现挂车对牵引车的转向运动进行主动跟随。文章建立连接装置、电液控制部分以及全挂车模型,仿真结果证明该转向系统具有稳定性。     

宏观·国内

<正>我国将在黑龙江开展超长汽车列车试点2015年7月27日,交通运输部对《关于黑龙江省龙运集团试点运营双挂列车的请示》进行批复,这标志着我国正式开展超长汽车列车试点工作。批复称,黑龙江省龙运集团借鉴国际先进经验,提出将货车、半挂车、中置轴挂车等货物运载单元进行组合,组成中置轴货车列车、超长汽车列车从事运输作业,并将汽车列车与甩挂、     

双轴转向挂车性能参数确定

双轴转向挂车具有转向半径小、机动灵活的特点，适合于场地狭窄情况的运输要求。介绍了一种双轴转向挂车的结构型式，并分析了不同方案的结构特点。通过双轴转向挂车列车转向过程的几何分析，导出了转弯半径、相邻两挂车铰接点的位置以及牵引杆的长度计算公式     

多转向模式组合的运梁车转弯半径分析

研究了一种四轮转向与铰接车架组合的主副车模式运梁车的结构形式,并对该形式运梁车的转向工况进行分析,得出了具有最小转弯半径的工况及确定方法和最小转弯半径的计算公式.结果表明：最小转弯半径工况的方法能够更好地确定最小转弯半径,可为具有同类结构的运梁车最小转弯半径的计算提供理论依据.     

汽车列车制动力分配和制动稳定性分析(下)

二、汽车列车的制动稳定性汽车列车制动时不发生列车折叠和挂车甩尾等现象的性能称为汽车列车的制动稳定性。产生折叠和甩尾现象是汽车列车在高速行驶制动时造成重大事故的主要原因之一。(一)汽车列车的自由度分析我们将参考坐标系设在牵引车上,坐标原点在牵引钩的中心,来分析挂车相对牵引车的自由度。     

Effects of multiple axles on the lateral dynamics of multi-articulated vehicles

This paper describes an analytical study of the lateral dynamics of multi-articulated vehicles with multiple axles. A linear planar model of vehicle dynamics is adopted for multiple-axle vehicle combinations with an optional number of trailers. Two tractor and double-trailer combinations are examined for their directional stability and response. Non-oscillatory stability and steering sensitivity in steady-state turning and lane changing are analysed using a stability factor of multiple-axle vehicle combinations. Off-tracking in the steady-state turning of multiple-axle vehicle combinations is also analysed. Numerical calculations for oscillatory stability, steering sensitivity, and off-tracking are presented for multiple-axle vehicle combinations.     

Ride Vibration Measurements of Agricultural Tractor and Trailer Combinations

Tractor ride vibration levels have been measured when operating with and without a two wheel (2W) unbalanced and a four wheel (4W) balanced trailer. Measurements were made in the vertical, pitch, longitudinal and roll directions with the trailers unladen and laden over four typical farm surfaces

The results showed that tractor ride vibration levels were usually increased in all directions-particularly the longitudinal direction- when operating with the laden trailers. But for the unladen trailers, they were increased only in the longitudinal direction. Predominant tractor frequencies tended to be lower with the trailers attached, and coupling between the tractor longitudinal, vertical, roll and pitch co-ordinates was generally increased

Comparisons of the results with the trends predicted by a simplified theoretical model of a tractor and 2W trailer, suggested that the model should be extended to include, (a) the roll direction, (b) more realistic ground inputs, and (c) a 4W trailer     

Ride Vibration Measurements of Agricultural Tractor and Trailer Combinations

SUMMARY

Tractor ride vibration levels have been measured when operating with and without a two wheel (2W) unbalanced and a four wheel (4W) balanced trailer. Measurements were made in the vertical, pitch, longitudinal and roll directions with the trailers unladen and laden over four typical farm surfaces

The results showed that tractor ride vibration levels were usually increased in all directions-particularly the longitudinal direction- when operating with the laden trailers. But for the unladen trailers, they were increased only in the longitudinal direction. Predominant tractor frequencies tended to be lower with the trailers attached, and coupling between the tractor longitudinal, vertical, roll and pitch co-ordinates was generally increased

Comparisons of the results with the trends predicted by a simplified theoretical model of a tractor and 2W trailer, suggested that the model should be extended to include, (a) the roll direction, (b) more realistic ground inputs, and (c) a 4W trailer     

机械系统分析软件ADAMS在汽车列车动力学仿真中的应用

本文应用机械系统分析软件ＡＤＡＭＳ建立了由一节牵引车和五节双轴转向拖车组成的汽车列车系统１３个自由度的动力学模型。采用模型参数化分析方法，讨论了牵引杆长度、主车与拖车和拖车与拖车的铰接点位置对主车与拖车轨迹同辙性的影响。以汽车列车移稳态圆周运动和８字型运动时主车与拖车轨迹同辙性为目标函数，对汽车列车进行了优化设计，获得了满意的优化方案。     

Lateral Dynamics of Commercial Vehicle Combinations A Literature Survey

This paper presents a review of theoretical and experimental works relative to the handling performance of commercial vehicle combinations. A commercial vehicle combination (road train) is defined as a tractor unit and an arbitrary number of trailers. The review contains literature corresponding the most widely used types of trains: tractor-semitrailer, truck-trailer and tractor-semitrailer-semitrailer (doubles). The vehicle dynamic performance has been investigated taking into consideration the following features: directional performance, roll dynamics, braking performance and combined braking and directional performance. With the aim of evaluating the present state of research activities in the field of lateral dynamics of articulated commercial vehicles, the author has compiled some 250 references.     

Lateral Dynamics of Commercial Vehicle Combinations A Literature Survey

SUMMARY

This paper presents a review of theoretical and experimental works relative to the handling performance of commercial vehicle combinations. A commercial vehicle combination (road train) is defined as a tractor unit and an arbitrary number of trailers. The review contains literature corresponding the most widely used types of trains: tractor-semitrailer, truck-trailer and tractor-semitrailer-semitrailer (doubles). The vehicle dynamic performance has been investigated taking into consideration the following features: directional performance, roll dynamics, braking performance and combined braking and directional performance. With the aim of evaluating the present state of research activities in the field of lateral dynamics of articulated commercial vehicles, the author has compiled some 250 references.     

蝴蝶领结型交叉口交通组织与几何参数计算

为消除平面交叉口左转交通对交叉口的瓶颈作用，采用蝴蝶领结型交叉口交通组织方式，禁止交叉口车辆左转，将左转车流引至次要道路的环岛处进行掉头，将左转车流变成直行车流，并根据车速、道路和交通条件推导了掉头环岛与交叉口的距离、半径和车道宽度的计算模型。经过蝴蝶领结型交叉口交通组织以后，使交叉口的车辆禁止向左行驶，促使冲突点减少且信号控制只需两个相位，能够将交叉口信号灯的利用率提升，对交叉口运行效率具有显著提升效果。     

全挂车轮转向装置设计

全挂车转向装置分为轴转向和轮转向两种形式，由于轮转向两种形式。由于轮转向装置转向角度小，制造工艺复杂。成本高，一般较少应用。便全挂车采用轮转向装置可降低车厢地板高度，且其机动性较轴转向全挂列车好，推导了轮转向传动连杆机构的解析关系式及优化设计目标函数和约束条件，并给出了相应算例。     

Method for control of steering angles for articulated vehicles using virtual rigid axles

Many methods we have been developed to control the rear wheels of a vehicle, but most of them are designed for automobiles with four wheels. The AWS (all wheel steering) control method for articulated vehicles is currently applied only to Phileas vehicles developed by APTS, but the control algorithm for this system has yet to be reported. In the present paper, a new algorithm is proposed after the AWS ECU (electronic control unit) of the Phileas vehicle was tested and analyzed in order to understand the existing steering algorithm. The new algorithm considers the vehicle geometry, stability of handling, and safety, and can be easily applied to multi-axle vehicles. In order to verify the AWS algorithm, the trajectory and steering angles of each algorithm were compared using the commercial software ADAMS. Turning radius, swing-out, and swept path width were also investigated to determine the turning performance of the proposed algorithm.