新型轻质材料在汽车发动机罩上的应用

在当今汽车工业界以节能和环保为研发目标的主旋律下,文章概述了在汽车材料中,使用新型轻质材料对于降低油耗和减少排放所做出的贡献.并根据汽车发动机罩的功用及其结构特点,系统地介绍了用于制造发动机罩的高强钢、铝合金、镁合金和复合材料等新型轻质材料.根据这些轻质材料各自的物理特性和加工成型特性,比较了其在汽车发动机罩上的应用,通过比较,分析总结了各种材料在发动机罩上应用的各自优缺点.结合汽车工业发展的过程及其要求,得出了新型轻质材料在发动机罩上的应用趋势.     

新型轻质材料在汽车发动机罩上的应用

文章系统介绍了用于制造发动机罩的各种新型轻质材料,并根据发动机罩的结构特点,比较了各种新型轻质材料在发动机罩上的应用.通过比较,分析了各种材料在发动机罩上应用的优缺点,并得出了新型材料在发动机罩上的应用趋势.     

TEEE中冷器管路的开发与应用研究

文中介绍了汽车发动机中冷器管路的特点,比较了硅橡胶与TEEE的性能特征。实验对比表明TEEE代替硅橡胶管应用于部分中冷器材料满足技术要求,开发应用轻质TEEE中冷器管路能够大幅度降低材料成本,具有显著的经济效益。     

基于行人保护的铝合金发动机罩盖结构优化设计

基于原钢质罩盖的行人头部保护性能,采用结构优化的设计方法,设计圆锥形内板结构的铝合金发动机罩盖。CAE仿真分析结果表明,在满足刚度性能要求的同时,铝合金罩盖具有更好的行人保护性能,且实现减重45.5%。同时为铝合金等轻质材料在汽车上的应用提供了借鉴作用。     

泡沫轻质土渗透及吸失水性能试验研究

通过对湿重度分别为5.5 k N/m³、6 k N/m³的泡沫轻质土进行渗透及吸失水试验，研究了泡沫轻质土的孔隙状态、渗透系数及吸失水性能。试验结果表明：气泡混合轻质土是一种高孔隙率材料，其孔隙占比在75%以上，渗透系数约为10^-5～10^-6数量级，介于粉质粘土与粘土的渗透系数之间；受水浸泡后，泡沫轻质土容重最大增加约25%，失水后容重仍然有约9.5%增加量，在工程设计中应根据不同置换路基施工环境对设计容重按照1.0～1.25之间进行修正。     

采用轻质材料制造的自卸半挂车

采用轻质材料,是减轻车辆自质量、降低发动机燃油消耗和提高车辆装载能力的重要手段之一,因而受到了许多厂商和主管部门的重视。在创造和采用“轻质”自卸半挂车方面,欧洲等地的许多厂商可谓是走在了世界的前头,而我国则还很原始。在燃料紧缺、运价回升(至正常水平)的形势下积极学习他们的技术和经验显得十分必要。     

轻质混凝土桥面铺装材料耐久性能的研究

桥面铺装材料采用轻质混凝土能够降低桥面自重,相对提高桥梁承载能力,但桥梁因其服役的特殊环境对采用材料的耐久性能提出较高的要求,因此文章通过与普通混凝土对比,研究了钢纤维聚合物轻质混凝土抗渗、干缩和抗冻等耐久性能。实验表明:当钢纤维体积掺量为1.0%时,轻质混凝土的抗渗透等级达P12以上;90天干缩率为2.77×10-4;冻融循环300次后,相对动弹性模量96%,质量损失率0.5%。     

最强怪兽 2016 Ducati MONSTER 1200 R

<正>采用铝合金锻造轮辋、碳纤维前挡泥板等轻质材料,整车净质量降至180kg;强化Testastretta 11°DS发动机动力输出,最大功率增长了10%,最大扭矩增强了5.5%;优化人机三角,在维持乘骑舒适的前提下,提升了操控性能;高规格的车架设置,无论是快速攻弯,还是高速狂飙,都显得沉着稳定、胸有成竹;历史已经超过20年的杜卡迪"怪兽"家族,现在郑重宣布,新一代旗舰震撼出击!     

272发动机二次空气喷射系统

272发动机是V型6缸发动机,采用轻质材料设计而成,每缸4个气门,排量为3.5 L,配有进气和排气都可调凸轮轴,其结果是既提升了性能潜力,又减轻了质量。另外,6缸动力单元内的燃烧过程经过优化,降低了废气排放量和燃油消耗量。S350峰值扭矩为350 Nm,最大输出功率为200 kW（即272马力）。     

玻璃钢复合材料驱动汽车轻量化发展

众所周知,减少燃料消耗和降低对环境的污染,已成为汽车工业发展和社会可持续发展要解决的关键问题。采用高性能轻质材料是实现汽车轻量化的一条重要途径,可以有效地减轻汽车自重,提高发动机效率。本文从玻璃钢复合材料的特点及工艺要求等方面介绍了该材料在汽车产品上广泛的应用前景。     

丰田2JZ-GE发动机气门驱动机构与气门间隙的调整

丰田皇冠2JZ-GE发动机为水冷直列6缸4气门电控直喷式发动机，其气门由顶置双凸轮轴直接驱动。由于其气门升程比摇臂式气门低，所以气门间隙的调整比较困难。结合图例介绍了气门间隙的测量与调整。     

Modeling and simulation of a dual-mode electrohydraulic fully variable valve train for four-stroke engines

In modern four-stroke automotive engine technology, variable valve timing and lift control offer potential benefits for making a high-performance engine. In this paper, a novel design named dual-mode electrohydraulic fully variable valve train (EHFVVT) for both engine intake and exhaust valves is introduced. The system is mainly controlled by either proportional flow control valves or proportional pressure relief valves, and hence two different families of valve displacement patterns can be achieved. The construction of the mathematical model of the valve train system and its dynamic analysis are also presented in this paper. Experimental and simulation results show that the dual-mode electrohydraulic variable valve train can achieve fully variable valve timing and lift control, and has the potential to eliminate the traditional throttle valve in the gasoline engines. With the proposed system, the engine performance at various speeds and loads will be significantly improved.     

CA6102型发动机气门与气门座的配合性能

在FQM－1型气门、气门座模拟摩擦磨损试验机上，进行了一系列CA6102发动机气门与气门座的配合性能试验。对21－4N气门材料与V431、V431－Nb＋Ti、高MnAl、粉末治金及表面镶CrN等各种材料气门座的配合性能做了全面的试验研究，得出了材料、工艺等因素对气门、气门座耐磨性的影响规律。     

一种气门间隙的两次调整法

根据发动机曲轴、曲柄布置规律和气门开闭规律,先找出进排气门都开启的缸,再找出与其相对应的进排气门都关闭的缸,然后确定可调气门,结果表明这种方法适用于多缸四行程发动机的气门间隙调整.     

高速强力电磁阀的研究现状

介绍了4种"E"型电磁铁的优缺点,比较了滑阀式阀芯等4种阀芯结构,以响应速度和流量作为目标参数,分析了几种典型的电磁阀结构,结论是环状多极式"E"型电磁铁和锥阀式阀芯为电控喷油系统用高速强力大流量电磁阀较理想的结构形式。     

上海别克轿车V6发动机配气机构的检修

上海别克V6发动机配气机构为气门顶置、凸轮轴上置式，以齿形皮带同步传动。介绍了气门与气门座的检修；气门挺杆的检修；摇臂与摇臂轴的检修；气门导管的检修；气门弹簧的检修；凸轮轴的拆装与检修；凸轮轴油封的更换；气门推杆的检修；齿形皮带的安装。     

Electromagnetic valve train for gasoline engine exhaust system

Electromagnetic valve train (EMVT) in camless engine offers large potential for both part load fuel economy and high load engine torque. However, it is more difficult to be applied on exhaust system than intake system. Because the gas pressure brings high demands for driving force, especially at high engine speed and full load. Based on the working characters of actuator, a method by increasing the transient currents in windings during valve’s opening motion is suggested to overcome the gas pressure. But this will cause more energy losses and heat. In order to make the EMVT used on exhaust system better, quantitative analysis is carried out against the additional power consumption caused by gas pressure under different conditions. Furthermore, an approach is introduced to define the optimal exhaust valve opening motion at full load conditions. It aims at making a better compromise between the engine power output and exhaust valves’ power consumption, thus both the efficiency of EMVT and engine performance are enhanced.     

Influential factors for HLA pump up in a roller finger follower engine

In an HLA (hydraulic lash adjuster) piston engine, “pump up” can occur when a valve is opened by the HLA when it should be closed. HLA pump up is more frequently encountered with exhaust valves than with intake valves. When HLA pump up in occurs in the exhaust valve, exhaust gas from the exhaust manifold enters the cylinder on the intake stroke, and fresh air-fuel mixture exits through the exhaust manifold on the compression stroke and is burned in the catalyst, causing partial burning, misfire, catalyst melting and power drop. HLA pump up occurs when the force on the valve from the HLA is higher than the force on the HLA from the valve. HLA pump up is related to design parameters, such as oil pressure, rocker ratio, spring load, spring surge, and both intake and exhaust valve timing. In this study, valve lift and load on a roller finger follower were measured at varying engine firing conditions to evaluate HLA pump up. The results indicated that effective measures to reduce HLA pump up include a higher rocker ratio, a lower oil supply pressure to the HLA, a higher spring installation load and a lower spring surge.     

CA6110系列柴油机气门断裂分析与改进

CA6110AK与CA6110BK是在CA6110—1B柴油机的基础上进行强化的2种新机型，其标定功率由原117kW分别增加到125kW和132．5kW，但易产生气门断裂故障。介绍了气门断裂原因分析与改进，配气机构可靠性和动力学性能分析，凸轮型线改进。安装新凸轮、新弹簧及新气门的2台发动机200h可靠性试验后，配气机构无任何异常。     

柔性调节无凸轮配气机构设计与试验研究

设计了液压驱动柔性调节的无凸轮配气机构,分析了其工作原理和气门运动特性,试制了原理样机,通过对原理样机的试验研究获得了该配气机构的气门运动特性,提出了气门"软着落"方案,有效降低了气门落座冲击。该柔性调节配气机构可以实现气门提前角、气门开启持续时间(时面值)、气门迟闭角等参数的连续可变。将该柔性调节配气机构成功应用于液压自由活塞柴油机的排气门,试验效果良好。