SL6400A轻型客车驻车制动传动机构的改进

SL6400A轻型客车驻车制动器采用后桥车轮鼓式制动器，该车原驻车制动机构存在传动环节多、支座刚性差及拉索走向不合理等因素，致使左、右后轮制动力不平衡或不足，通过分析与对比，自行设计了一种新型驻车制动传动机构，该结构可通过平衡器的转动保证左、右后轮制动力不平衡或不足，通过分析与对比，自行设计了一种新型驻车制动传动机构，该结构可通过平衡器的转动保证左、右后拉索拉力相等。试验证明，驻车制动效果良好。     

汽车制动时摩擦力的形成

在汽车制动过程中，形成制动器制动力和地面制动力等两个摩擦力。地面制动力随着制动器制动力的增大而增加，但有其一定的限值，其最大值受路面附着力制约。为获得良好的汽车制动效果，制动器制动力不宜将车轮制动抱死，而保持车轮的滑移率为１５％－２０％是最佳状态。因此，在车轮制动器中设置制动防抱死系统。     

盘式制动器自增力系统设计

通过设计简单的压力转换装置，即在制动钳与转向节之间设置一个增力油缸，将汽车行驶动能部分转化为对制动器的增力。该自增力系统可以较好地解决动力源问题，又使制动系结构大大简化，降低制造成本，为盘式制动器的普及应用提供了条件，此外，由于该系统在制动时不消耗发动机动力，因而有显著的节能效果。     

汽车制动检验台的评述（二）

滚筒反力式制动检验台的评价。滚筒反力式制动检验台在检测过程中不受驾驶员操作状况的影响，检测工况稳定，检测结果可靠，多次检测的重复性好；检测时是滚筒推动车轮转动，因此，它可检测车轮阻滞力和驻车制动力；检测过程可包括制动器作用阶段和持续制动阶段，故可检查车轮的制动蹄摩擦片与制动鼓接触配合状态，判断制动鼓的圆度。     

西门子VDO电子楔式制动器

文章详细介绍了线控制动技术的最新发展——电子楔式制动器(EWB,Electronic WedgeBrake)。相比传统制动系统,这种自增力机电楔式制动系统所需制动力小、消耗能量低,但对控制系统的精确度要求较高。     

福特SCORPIO（天蝎座）轿车制动防抱系统及其测试

汽车的制动效果,主要取决于制动器的制动力,车轮与地面的附着力和滑移力。 实践证明,当滑移率在10％～30％之间制动力达到最大,超过30％后制动力逐渐下降。防抱制动装置的作用就是将汽车制动时车轮的滑移率控制在10％～30％之间,从而获得最佳制动效能,有效地缩短制动距离。 一、福特天蝎座轿车制动防抱系统     

制动抱死工况下轮毂电机端盖的可靠性分析

介绍了内转子式轮毂电机与盘式制动器的组合结构,分析了固定制动力分配时制动抱死工况下车轮的最大制动力,确定了轮毂电机关键结构负载,最后采用有限元法分析了轮毂电机端盖的可靠性.     

FZ-TS(A)型汽车制动检验台的使用与维护

一、制动力检测的原理 反力滚筒式制动检验台制动力的检测原理如图1所示。这种制动检验台不是直接测量滚筒所受的制动力，而是测量电动机所受的反作用力。测量时，将被检车的车轮置于两个滚筒上，由电动机通过减速器驱动滚筒，从而带动车轮旋转，当车轮制动时，车轮不再转动，车轮给滚筒一个与其旋转方向相反的力，该     

基于路面附着系数的制动力利用率评价法

为了考察在各种附着系数的路面上汽车的制动性能,分析了理想汽车前、后车轮制动力分配曲线与前、后制动器制动力分配曲线之间的匹配关系.引入能够反映制动性能的概念“制动力利用率”作为评价方法,根据不同的匹配关系导出对应的制动力利用率算法.针对某轻型客车,详细地分析了其在不同附着系数路面上的制动性能.同时改变制动器制动力分配系数,分析不同匹配关系下汽车的制动性能.结果表明:随着路面附着系数的增加,制动力利用率呈现先增后减的趋势;随着制动器制动力分配系数的增大,汽车在低附着系数路面的制动力利用率降低,在高附着系数路面的制动力利用率升高;制动力利用率评价法能够有效地评价汽车在不同附着系数路面上的制动性能.     

关于汽车用低气压在反力式制动试验台上检验制动力的问题

一、引言目前,汽车在反力式制动试验台上检验制动力时,一般都是在空车情况下进行的。对于气压传动的制动系来说,其制动力的检验方法可分为加载试验和低气压试验两种。在反力式制动试验台上,检验制动力的大小,受车轮与滚筒的附着条件所限止。采用加载试验法时,由于加载的结果,增大了车轮的附着重量,可以在试验台上直接测出车轮的最大制动力;而低气压试验法,是在制动系空气压力降低了的情况下检验的,它只能测出制动力的某个中间值,根据这个中间值来判断制动器性能的好坏。     

一种叶轮式MRF汽车制动器结构设计与性能仿真

设计了一种汽车轮内叶轮式磁流变液制动器,推导出该制动器的制动力矩计算方法,并在Matlab/Simulink环境下建立仿真模型,分析了制动器结构参数对制动力矩的影响。结果表明,叶轮式磁流变液制动器工作模式为剪切与流动的混合模式,其制动力矩与磁感应强度呈现对数变化规律,与工作间隙呈现负指数变化规律;叶片的径向尺寸、叶片数量和叶片厚度对制动力矩都有较大影响。所设计的汽车磁流变液制动器能够满足一般小型汽车的制动力矩需求。     

Design and use of an eddy current retarder in an automobile

In this study, the structure and working principles of an eddy current retarder acting as an auxiliary brake set is introduced in detail. Based on the principle of energy conservation, a mathematical model was developed to design a retarder whose nominal brake torque is 1, 900 N·m. According to the characteristics of the eddy current retarder, an exclusive test bed was developed and used for brake performance measurements. The main technical parameters, such as the brake characteristics, temperature characteristics and power consumption, were measured with the test bed. The test data show that the brake torque of the eddy current retarder obviously decreased in the continuous braking stage and that there is a certain amount of brake torque in the normal driving state because of the remnant magnetism of the rotor plate. The mathematical model could be used to design an eddy current retarder. The exclusive test bed could be used for optimization of an eddy current retarder as well as for R&D of a series of products.     

钳盘式和片式制动器设计计算

针对钳盘式制动器和片式制动器各自的优点,详细介绍了它们的制动力矩的设计计算,以及对制动器摩擦片进行耐压、耐磨损的温升等验算.     

鼓式制动器制动力矩的计算研究

本文建立鼓式制动器力学模型，用三种方法对该制动器制动力矩进行了计算。通过对计算结果和试验结果进行了对比分析，建立了准确而有产的制动力矩计算方法，在此基础上，研究了制动补片材料摩擦系数等参数对制支力矩的影响。     

现代汽车制动器制动间隙自调装置的结构与原理

介绍了双向自增力式制动器中的拉索型和杠杆型制动器的制动间隙自调装置的结构和工作原理；对领从蹄式制动器的螺纹推杆型制动间隙自调装置、棘齿型制动间隙自调装置和凸轮型制动间隙自调装置的结构和工作原理进行了分析和研究。     

Coordinated vehicle traction control based on engine torque and brake pressure under complicated road conditions

Vehicle traction control system has been developed to enhance the traction capability and the direction stability of the driving wheels through the tyre slip ratio regulation. Under normal situations, if the tyre slip ratio exceeds a certain threshold, the slip ratio of the driving wheel is regulated by the coupled interaction of the engine torque and the active brake pressure. In order to obtain the best driving performance on a road under complicated friction conditions, the driving torque and the active brake pressure, need to be decoupled and adjusted to avoid penalisation of each other. In this paper, a coordinated cascade control method with two sliding-mode variable structure controllers is presented. In this control method, the driving wheel slip ratio is regulated by adjusting the engine torque and the wheel brake pressure. Through the sliding-mode controller, the engine torque is tuned to achieve the maximum driving acceleration and then the active brake pressure is applied to the slipped wheel for further modification of the wheel slip ratio. The advantage of this control method is that through proper regulation, the conflict between the two control inputs could be avoided. Finally, the simulation results validate the effectiveness of the proposed method.     

具有双离合器的液力变矩器的结构设计

将液力变矩器与机械式自动变速器合理匹配可组成一种新型自动变速系统，其性能接近自动变速器，但成本降低。为该系统设计了具有双离合器(闭锁离合器，换档离合器)的液力变矩器。阐述了该液力变矩器的结构、工作原理及特点。试验结果表明，所设计液力变矩器可支持新型自动变速系统成为现实。     

A Variable Free Control Characteristic Vehicle

A variable characteristic car (VCC) has been developed at Melbourne University for driverlvehicle handling research. The vehicle is unusual in that it has facilities for varying both its fixed control and free control dynamic characteristics over wide ranges. In this paper the servo systems used to effect these changes are described. The calibration methods used to relate the vehicle response characteristics to the variable servo settings are detailed. Sample calibration results are given for the fixed control parameters steering ratio, yaw response time and stability factor. Calibration of the free control parameters is also described and results are given for the steering torque gradient, and the time-to-peak and percentage overshoot of the steering wheel motion in response to a step input of torque.     

鼓式制动器制动时前轮摆振的原因分析

针对某中型货车制动时前轮摆振现象,从理论上分析了前轮摆振的产生机理,先对振动现象进行检测分析,再改进制动器的结构,然后通过整车试验和制动器台架试验对改进进行了验证。试验和分析的结果表明：制动时前轮摆振是车辆制动过程中前制动器的制动力矩波动造成的,与制动器结构有关,通过改进制动器这个摩擦系中的摩擦体的刚性,不仅可以消除制动时的前轮摆振,同时还可大幅提高制动性能。     

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.