汽车内饰顶棚总成的生产工艺

汽车内饰顶棚是整车内饰的重要组成部分,兼具装饰性与实用性。文章介绍了汽车内饰顶棚总成的构成、标准要求和安装方式,分析了热塑性基材和热固性基材的特性;重点介绍了聚氨酯模塑顶棚总成的干法工艺和湿法工艺、设备和模具的要求及对比。聚氨酯一体模塑顶棚在汽车内饰顶棚领域越来越占主流性的地位,轻量化和绿色环保化是汽车内饰顶棚的发展趋势。     

汽车顶棚总成VOC性能的改善研究

为解决车内易挥发有机物（VOC）污染问题，以汽车顶棚总成为例，通过对其产品及原材料VOC检测、生产工艺和储存环境影响与分析，提出相应的改进措施和方法，从而开展基于材料、零部件及成形工艺的汽车顶棚总成低VOC绿色设计与开发，为主机厂和配套商提供汽车顶棚总成VOC溯源分析和低VOC材料工艺解决方案。     

汽车顶棚概论与设计

文章介绍了汽车顶棚的分类、材料、成型、加工、安装、性能和实验等基本属性和要求。针对顶棚的制造工艺、装配工艺、设计风险,提出以关键断面定义为设计手段,对汽车顶棚各个重要区域的关键断面,结合自身造型、周边件的尺寸、制造和装配工艺、安全法规、人机工程等相关因素进行定义。通过简介和深入设计分析的两个方面,实现对汽车顶棚基本知识和结构设计的描述,为内饰设计工程师优化设计提供借鉴。     

乙烯脲在湿法顶棚工艺中的除醛应用研究

为解决汽车内饰顶棚产品中醛类物质含量易超标问题,采用“一步湿法”工艺,将乙烯脲添加到汽车内饰顶棚样品的生产过程当中。测试了乙烯脲添加量对样品甲醛、乙醛含量的影响,并研究分析了添加乙烯脲的样品中醛类物质含量随时间的变化,研究表明,通过向顶棚样品中添加乙烯脲,可以大幅降低产品的醛含量,添加过程操作简便,处理后的产品,醛含量可以长时间保持在较低水平。     

湿法和干法SBS改性沥青混合料对比研究

为了比较湿法和干法两种工艺生产的SBS改性沥青混合料的性能,在分析SBS改性机理基础上,对两种工艺生产的SBS改性沥青混合料路用性能进行了试验研究。结果显示,与湿法工艺相比,干法工艺除了具有生产工艺简单、配方更改方便、节能效果明显等特点之外,干法工艺生产的SBS改性沥青混合料在高温稳定性和水稳定性方面更优越。     

提升湿法顶棚气味品质的措施

为提高湿法顶棚气味品质,对组成湿法顶棚中的PU板、骨架胶、玻纤毡、无纺布、面料胶、针织复合面料、包边胶的气味来源进行分析并提出改善措施,通过分析得知湿法顶棚中的气味来源于原材料本身或配方中产生的小分子物质,最终通过对原材料与配方的气味改善使湿法顶棚气味品质得到提升。     

克拉玛依沥青改性工艺对比研究

为评价湿法、干法工艺对克拉玛依沥青的适用性,分别采用常规SBS改性剂、干投型SBS-T改性剂制备改性沥青,采用干法、湿法两种工艺拌制改性沥青混合料,对其路用性能进行测试。结果显示,在同一针入度等级的情况下,使用干法改性剂制备的改性沥青的高低温指标优于湿法;使用干法工艺制备的改性沥青及改性沥青混合料的性能指标能满足规范要求,干法技术制备的改性沥青混合料的车辙动稳定度远高于湿法,强度、抗疲劳性能和抗水损害性能也有所提升;成品改性沥青在储存过程中性能指标发生一定变化,通过结合料评价并不能完全表征这种变化;对克拉玛依沥青改性时建议采用干法工艺。     

汽车顶棚内饰设计

简述了汽车顶棚内饰有软顶、硬顶两种形式，安装方式主要有粘贴、吊装、粘接和镶嵌，汽车顶棚内饰材料的发展趋势是高强度模塑基材等，详细说明了汽车应顶顶棚的基材，如聚苯乙烯、聚氨酯、聚丙烯、聚丙烯蜂窝材料等。介绍了制造顶棚内饰的隔热、吸声设计。     

不同复合基材在汽车内饰顶棚上的应用

分析了半固化纺织绵毡、麻纤维板、PP和PU等不同材质、不同结构的复合基材在汽车内饰顶棚方面的应用情况,研究、对比了各种基材顶棚的吸音性能等各项物理、力学综合性能,着重介绍了PU基材顶棚的各项性能指标,并与某合资品牌车型标准进行了对比、分析,为各类车型汽车内饰顶棚基材选择提供参考。     

汽车内饰顶棚隔热性能与材料结构优化试验研究

介绍了常用汽车内饰顶棚的基本结构与性能要求,提出顶棚多层隔热材料的结构设计方法和隔热理论基础,利用瞬态平面热源法测得基材和复合材料导热系数,优选导热系数小及反射热波能力强的材料制成复合隔热材料,借助于汽车乘员舱模型中的多种复合材料隔热性能试验比较,给出汽车内饰顶棚最优复合材料构成。试验结果表明,优选复合隔热材料与某原有车用材料的热流透过率相比可以减少超过10%。     

基于三维扫描顶衬与遮阳帘高精度尺寸策略研究

针对传统顶衬与遮阳帘尺寸策略问题,利用三维扫描技术收集物体几何表面的点云创建模型,并提供进行自动化尺寸策略评估的一种数字化工程解决方案,并对比传统意义上的车辆工程开发中顶衬与遮阳帘物理尺寸验证与数据收集工作优势,并以某项目新车型中三维扫描技术的实际案例出发,简述了三维扫描技术如何针对顶衬与遮阳帘尺寸质量优化进行指导,以及顶衬与遮阳帘零件尺寸质量提升工作中的优势。     

拉臂钩在拉臂车制造过程中的控制要点

拉臂钩是车厢可卸式汽车的关键部件,其性能的好坏决定着整车的优劣,拉臂钩安装到底盘上的生产制作过程,是保障拉臂钩整体性能的重要环节,也是专用车企业重点控制的关键工序。通过介绍拉臂车生产制造的流程,结合实际生产中安装的经验和体会,阐述了拉臂车在生产制造中的过程控制要点。     

干法生产加工机制砂关键技术

机制砂是岩石经除土开采、机械破碎、筛分制成的粒径在4.75 mm以下的岩石颗粒。砂岩、石灰岩石质是生产加工机制砂较为理想的矿山材料,根据不同的地理位置条件选取不同的生产方法,利用干法、湿法、筛分法等不同方法,均能生产出合格的机制砂,但控制砂中石粉含量是干法生产加工机制砂的关键要点。机制砂生产与碎石连产,降低生产成本,充分利用废料,节约生产加工场地。该文介绍了机制砂生产加工的技术要点。     

整车装配工艺规划应用及研究

随着我国科技事业的不断发展,汽车方面的建设也在随之迅速发展,对于汽车设计开发到实际生产导入转化,汽车总装负责最后的装配、调整和检验工作,也是汽车生产过程中投入人力最多的领域。面对车辆产品智能水平升高、配置越发丰富,合理的整车装配工艺显得尤为重要,可以规避实车制造后期发现问题后难整改、周期长等问题。如何合理制造出高质量、高效率、低成本的产品,本文针对整车工艺规划的模块化方案分析及供货层级制定、工艺路线制定、零部件装配层级分布图、数模工序装配模拟仿真及工艺卡编制的应用进行分析及总结,以期能总结相关经验作为参考材料。     

Estimation of Tire-Road Friction Using Observer Based Identifiers

This paper presents methods for identifying the tire-road friction coefficient. The proposed methods are: an observer-based least square method and an observer/filtered-regressor-based method. These methods were designed assuming that some of the states are not available since physical parameter identification methods developed assuming that the system states are available are not attractive from a practical point of view. The observer is used to estimate signals which are difficult or expensive to measure. Using the estimated states of the system and the filtered-regressor, the parameter estimates are obtained. The proposed methods are evaluated on an eight state nonlinear vehicle/transmission simulation model with a Bakker-Pacejka's formula tire model. Vehicle tests have been performed on dry and wet roads to verify the performance of the methods. It has been shown through simulations and vehicle tests how the RPM sensors can be used with observer based identification methods to estimate the tire-road friction from measurements of engine rpm, transmission output speed and wheel speed. The proposed methods will be useful in the implementation and adaptation of vehicle collision warning/avoidance algorithm since the tire-road friction can be estimated only using the RPM sensors which are currently being used in production vehicles.     

Robust control for 4WS vehicles considering a varying tire-road friction coefficient

A µ-synthesis for four-wheel steering (4WS) problems is proposed. Applying this method, model uncertainties can be taken into consideration, and a µ-synthesis robust controller is designed with optimized weighting functions to attenuate the external disturbances. In addition, an optimal controller is designed using the well-known optimal control theory. Two different versions of control laws are considered here. In evaluations of vehicle performance with the robust controller, the proposed controller performs adequately with different maneuvers (i.e., J-turn and Fishhook) and on different road conditions (i.e., icy, wet, and dry). The numerical simulation shows that the designed µ-synthesis robust controller can improve the performance of a closed-loop 4WS vehicle, and this controller has good maneuverability, sufficiently robust stability, and good performance robustness against serious disturbances.     

橡胶粉改性沥青混合料路用性能试验研究

采用湿法和干法2种工艺制备橡胶粉改性沥青混合料,对比分析基质沥青混合料、湿法工艺ARAC-13沥青混合料、干法工艺ARAC-13沥青混合料3种沥青混合料的高温稳定性、水稳定性及低温抗裂性能。研究结果表明：随着水泥替代矿粉比例增加,沥青混合料的路用性能先提高,后降低;橡胶粉改性沥青混合料水稳定性优于基质沥青混合料;ARAC-13W沥青混合料低温抗裂性能优于ARAC-13D沥青混合料性能;40目橡胶粉掺量为21％、水泥替代矿粉的比例为60％时,水泥橡胶粉复合改性沥青混合料路用性能最佳。     

Starting sliding mode variable structure that coordinates the control and real-time optimization of dry dual clutch transmissions

This paper researches the coordination of control between an engine and clutch at the system level to adequately reflect a driver’s intention and improve the starting performance of a vehicle equipped with a dry dual clutch transmission (DCT). Four-degree-of-freedom (DOF) starting dynamic equations are established for a dry DCT with a single intermediate shaft, and a two-DOF model of the sliding friction process and a single-DOF in-gear model of stable operation are obtained after simplifying these equations. Taking advantage of predictive control and a genetic algorithm, target tracing curves of the engine’s speed and the vehicle’s velocity are optimally specified online, and the starting sliding mode variable structure (SMVS) coordinating control strategy is designed to track these curves. The starting performance of a prototype car equipped with a dry DCT is simulated under different starting cases on the MATLAB/Simulink software platform. The simulation results show that the designed SMVS coordinating controller not only embodies driver intention and effectively improves the dry DCT car’s starting performance but is also highly robust when subjected to variations in the vehicle parameters.     

客车中涂漆的干湿打磨工艺

通过对11m公路客车中涂漆的干打磨与湿打磨工艺操作、质量、成本的优劣对比,从而选择最佳的中涂漆干打磨与湿打磨组合。     

Development of a slip control anti-lock braking system model

This paper describes the initial phase of work carried out as part of an on going study investigating the interaction between the tyre, suspension system and an antilock braking system (ABS). The modelling, analysis simulations and integration of results have been performed using an industry standard Multibody Systems Analysis (MBS) program. A quarter vehicle model has been used together with an individual front suspension system represented by interconnected rigid bodies. The tyre model used can be integrated into vehicle handling simulations but only the theory associated with the generation of longitudinal braking forces is described here. An ABS model based on slip control has been used to formulate the braking forces described in this paper. The simulations, which have been performed braking on wet and dry road surfaces, compare the performance of two different tyres.