汽车转向直拉杆断裂分析

某厂生产的汽车转向直拉杆在拆卸时突然断裂。为查明断裂原因,防止类似问题的发生,对断裂的直拉杆进行了理化检验和分析。结果表明,直拉杆的接头与杆体在模具上一次铆压成型时,接头轴线与模具的轴线发生了偏斜,以致挤压时有悬空,从而导致了直拉杆杆体的剪切开裂。     

浅谈客车前轮摆振及其主要影响因素

探讨造成前轮摆振的主要因素及如何布置转向纵拉杆以避免悬架导向杆与转向杆发生运动干涉。     

汽配市场转向拉杆球接头的现状及危害

汽车转向拉杆球接头是汽车转向系中连接传动杆系的部件,包括纵拉杆球接头和横拉杆球接头。转向拉杆球接头由球头销、球座、弹簧、调节螺塞和开口销(或弹性挡圈)等组成。球头销的球头和球座组成球面运动副。转向系与汽车的安全性能有关,因此,转向拉杆球接头应具有足够的强度、刚度、可靠性、耐磨性和使用寿命,以避免因零件的损坏而造成严重事故。转向拉杆球接头使用中发生磨损,应及时进行调整或更换。     

转向横拉杆弹性对车辆操纵稳定性的影响研究

为了研究转向横拉杆的弹性对车辆操纵稳定性的影响,利用ADAMS软件建立了某轿车的多体动力学模型并进行了操纵稳定性的仿真分析。对于操纵稳定性的稳态特性,采用了ISO4138标准,在车辆行驶100 km/h下的固定圆周转向规程来进行评价;对于瞬态操纵稳定性特性,则采用ISO7401标准中方向盘扫频输入的响应特性来进行评价。仿真结果表明,转向横拉杆的弹性与轿车操纵稳定性的不足有很大关系,如果弹性横拉杆刚性过大,则需要1个较大的转向传动比以弥补其不足转向特性。因此,在汽车设计开发中,必须将转向横拉杆的弹性特性和转向传动比综合平衡考虑,两需要很好的匹配才能保证其具有良好的操纵稳定性。     

大客车转向系统设计探讨

本对大客车转向系统设计的有关问题如转器的选型与布置、前轮最大转角的确定、转向直拉杆系统的设计等进行了分析和探讨。     

半挂牵引车悬架转向系统干涉模型及运动学分析

半挂牵引车制动时悬架系统与转向系统存在干涉而引发制动时跑偏是共性问题,严重影响车辆高速制动时的稳定性与安全性.机构运动学分析是检验干涉并进行结构优化的重要手段.文中建立悬架与转向系统的干涉空间数学模型,研究不同制动强度下悬架跳动量与纵扭角度的变化规律,得到转向直拉杆与转向节臂球销中心的运动轨迹运动学模型,进而通过对比转...     

新能源轻卡转向系统零部件轻量化浅析

目前新能源轻卡转向系统根据载荷不同,采用EHPS或EPS。EHPS转向系统由转向盘总成、转向管柱带中间轴总成、循环球液压转向器、转向直拉杆总成、转向油泵带电机总成、动力转向油壶总成和动力转向高低压油管等零部件组成。EPS转向系统由转向盘总成、转向管柱带中间轴总成、循环球电动助力转向器(X-EPS)和转向直拉杆总成组成。文章主要对两种转向系统相关零部件轻量化进行简单分析。     

基于PROE的转向杆系装配方法优化及模型运动分析

正运用PROE做转向杆系校核时,拉杆装配大多采用两端球连接,但是这样有一个弊端,即拉杆可以随意转动,以至无法准确校核拉杆与其他零部件的间隙。现介绍一种装配方法,能够较准确的模拟拉杆转动时的运动情况。1球头总成装配因为汽车的转向车轮有外倾角、前束角,主销有后倾角和内倾角,所以转向时及车轮上、下跳动时转向拉杆一般做空间运动。为此,传动机构的关节处应用球头销(球铰)铰接。现以重汽某     

转向直拉杆预紧弹簧对稳态转向特性的影响

在模拟计算和试验验证的基础上,分析了CA141型汽车转向直拉杆预紧弹簧的不同预紧力对稳态转向特性的影响。     

客车转向拉杆系统角传动比的分析和选择

对转向拉杆系统角传动比、转向机摇臂摆角的有效利用率、方向盘转动的总圈数对客车操纵稳定性的影响以及这些数值之间的内在联系进行分析;最后对客车转向拉杆系统角传动比作出推荐。     

Effect of vertical and lateral coupling between tyre and road on vehicle rollover

The vehicle stability involves many aspects, such as the anti-rollover stability in extreme steering operations and the vehicle lateral stability in normal steering operations. The relationships between vehicle stabilities in extreme and normal circumstances obtain less attention according to the present research works. In this paper, the coupling interactions between vehicle anti-rollover and lateral stability, as well as the effect of road excitation, are taken into account on the vehicle rollover analysis. The results in this paper indicate that some parameters influence the different vehicle stabilities diversely or even contradictorily. And it has been found that there are contradictions between the vehicle rollover mitigation performance and the lateral stability. The direct cause for the contradiction is the lateral coupling between tyres and road. Tyres with high adhesion capacity imply that the vehicle possesses a high performance ability to keep driving direction, whereas the rollover risk of this vehicle increases due to the greater lateral force that tyres can provide. Furthermore, these contradictions are intensified indirectly by the vertical coupling between tyres and road. The excitation from road not only deteriorates the tyres’ adhesive condition, but also has a considerable effect on the rollover in some cases.     

微型汽车操纵稳定性问题探讨

运用汽车操纵动力学理论，结合微型汽车的结构特点和生产特点，从设计，制造，调整等几个方面对微型汽车普遍存在的转向沉重，回正不好，直线行驶跑偏，路感差，轮胎差异磨损等操纵稳定性问题进行了全面系统的分析研究，同时对汽车直线行驶稳定试验及评价方法进行了初步探讨。     

Numerical Simulation of Vehicle Behavior during Straight Line Keeping on Undulating Road Surfaces

Numerical design of vehicles having optimal straight line stability on undulating road surfaces requires an accurate vehicle model based on knowledge of the relevant phenomena. Therefore, vehicle behavior on undulating straight roads has been analyzed and modeled. Measurements on a flat road surface have shown that the dedicated vehicle model yields accurate simulation results of the steering response to medium steering wheel angle inputs. In addition, the model has been validated by measuring two vehicle responses during normal driving on an undulating straight road: viz. the responses to the small steering wheel angle input and to the input by the global inclination of the road surface.     

Numerical Simulation of Vehicle Behavior during Straight Line Keeping on Undulating Road Surfaces

SUMMARY

Numerical design of vehicles having optimal straight line stability on undulating road surfaces requires an accurate vehicle model based on knowledge of the relevant phenomena. Therefore, vehicle behavior on undulating straight roads has been analyzed and modeled. Measurements on a flat road surface have shown that the dedicated vehicle model yields accurate simulation results of the steering response to medium steering wheel angle inputs. In addition, the model has been validated by measuring two vehicle responses during normal driving on an undulating straight road: viz. the responses to the small steering wheel angle input and to the input by the global inclination of the road surface.     

装备EPS系统特锐样车操纵稳定性客观评价

对装备电动助力转向(EPS)系统的整车操纵稳定性进行评价的必要性进行了分析,介绍了装备EPS的整车操纵稳定性评价的具体内容。给出装备EPS的特锐样车原地转向轻便性、转向盘中间位置操纵稳定性、转向回正性、转向瞬态响应特性(转向盘转角脉冲输入)的试验方法和标准,对其操纵稳定性进行了评价。评价结果表明,所采用的评价方法有效、可行。     

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.     

4WS汽车操纵稳定性建模和仿真研究

从改善汽车操纵稳定性角度出发,全面考虑轮胎载荷、转向系等对四轮转向汽车操纵稳定性的影响,建立4WS（4 Wheel Steering System）整车操纵稳定模型。并用Matalab/simulink进行了模拟仿真研究。比较性地研究汽车在低速和高速时控制方式的特点和不同之处。本模型为4WS汽车设计改进优化提供一种手段和方法,同时,为4WS汽车理论研究和试验校核提供了参考。     

Desired yaw rate and steering control method during cornering for a six-wheeled vehicle

This paper proposes a steering control method based on optimal control theory to improve the maneuverability of a six-wheeled vehicle during cornering. The six-wheeled vehicle is believed to have better performance than a four-wheeled vehicle in terms of its capability for crossing obstacles, off-road maneuvering and fail-safe handling when one or two of the tires are punctured. Although many methods to improve the four-wheeled vehicle’s lateral stability have been studied and developed, there have only been a few studies on the six-wheeled vehicle’s lateral stability. Some studies of the six-wheeled vehicle have been reported recently, but they are related to the desired yaw rate of a four-wheeled vehicle to control the six-wheeled vehicle’s maneuvering during corning. In this paper, the sideslip angle and yaw rate are controlled to improve the maneuverability during cornering by independent control of the steering angles of the six wheels. The desired yaw rate that is suitable for a six-wheeled vehicle is proposed as a control target. In addition, a scaled-down vehicle with six drive motors and six steering motors that can be controlled independently is designed. The performance of the proposed control methods is verified using a full model vehicle simulation and scaled-down vehicle experiment.     

汽车在对开路面上的制动稳定性研究

以汽车动力学模型和汽车制动稳定性控制原理为基础,通过分析汽车两侧车轮在路面附着系数相差较大的对开路面上的紧急制动状况进行理论分析,提出运用主动转向技术控制汽车的方向稳定性,并使汽车在制动驶偏后能快速通过转向控制恢复到正确的行驶车道。     

Nonlinear optimal integrated vehicle control using individual braking torque and steering angle with on-line control allocation by using state-dependent Riccati equation technique

This paper proposes the solution of state-dependent Riccati equation as a nonlinear optimal regulator to stabilise the motion dynamics of the vehicle model subjected to sudden disturbance inputs in the lateral direction. The proposed nonlinear regulator coordinates individually actuated wheel braking torque and steering wheel angle simultaneously in an optimal manner. Performance criteria are satisfied by solving the Riccati equation based on the given cost function subjected to the nonlinear vehicle dynamics. On-line control allocation in terms of optimal brake torque distribution enhanced by optimal wheel steering angle input is achieved. Furthermore, the proposed optimal nonlinear regulator is an active fault-tolerant control system against partial by-wire actuator failures while guaranteeing stability with good performance due to its capability to allocate the individual control inputs in an optimal way. The main aim is to stabilise the motion dynamics of the vehicle model during short-term emergency situations along the desired straight trajectory manageable by average drivers and to provide vehicle stability and handling predictability through the interaction of individual wheel braking and steering actuators. Simulation results are used to illustrate the effectiveness of the proposed methodology.