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排序方式: 共有57条查询结果,搜索用时 46 毫秒
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通过分析某轿车底盘油管的试制成形工艺,改进了原加工工艺方案及加工方法,设计制造了具有快换式凸模结构的扩口模,从而减少了模具数量,降低了加工费用。生产实践证明:该模具结构合理、可靠、工作稳定,能保证产品质量,对相同类型零件的模具设计具有参考作用。 相似文献
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王培玲 《小型内燃机与摩托车》2004,33(2):44-44,46
本文通过采用同一辆受试摩托车在三种不同摩托车底盘测功机上进行比对试验的方法,考核分析了天津大学科达测控技术公司研发的“DPC-1型底盘测功机”的测试数据的准确性和精度。 相似文献
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The effect of ethanol-gasoline blends on criteria air pollutant emissions was investigated in a four-stroke motorcycle. The ethanol was blended with unleaded gasoline in four percentages (3, 10, 15, and 20% v/v) and controlled at a constant research octane number, RON (95), to accurately represent commercial gasoline. CO, THC, and NOx emissions were evaluated using the Economic Commission for Europe cycle on the chassis dynamometers. The results of the ethanol-gasoline blends were compared to those of commercial unleaded gasoline with methyl tert-butyl ether as the oxygenated additive. In general, the exhaust CO and NOx emissions decreased with increasing oxygen content in fuels. In contrast, ethanol added in the gasoline did not reduce the THC emissions for a constant RON gasoline. The 15% ethanol blend had the highest emission reductions relative to the reference fuel. The high ethanol-gasoline blend ratio (20%) resulted in a less emission reduction than those of low ratio blends (< 15%). This may be attributed to the changes in the combustion conditions in the carburetor engine with 20% ethanol addition. Furthermore, the influence of ethanol-gasoline blends on the reduction of exhaust emissions was observed at different driving modes, especially at 15 km/h cruising speed for CO and THC and acceleration stages for NOx. 相似文献
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《International Journal of Hydrogen Energy》2019,44(2):1239-1252
Concerns as to the adverse effects of diesel engine exhaust on urban air quality have resulted in increasingly stringent emissions legislation, with the prospect of many major global cities potentially banning diesel vehicles. Emissions of nitrogen oxides (NOx) and particulate matter (PM) are linked to increases in premature mortality, and the simultaneous control of both pollutants through modified combustion strategies presents a significant challenge. In this work, the effects of displacing diesel fuel with hydrogen on exhaust emissions were investigated in both a single cylinder research engine and in a demonstration vehicle. In the initial stage, tests were undertaken on a supercharged, direct injection, single cylinder diesel research engine at different engine loads, intake air pressures and EGR levels. Hydrogen was aspirated with the intake air, and EGR was simulated by supplying the intake pipe with compressed nitrogen gas. The results showed a reduction in CO2 and particulate emissions with increasing H2 addition, and an increase in NOx emissions at H2 levels greater than 10% of the total input energy to the engine. The next stage involved tests on a chassis dynamometer with a small van equipped with the multi-cylinder version of the single cylinder research engine. The van was fitted with a programmable H2 augmentation system, with H2 addition levels specified by accelerator pedal position. During full drive cycle tests conducted with and without H2 augmentation up to 10%, an average rate of 1 kW of H2 was supplied to the engine. With H2 augmentation, over the total drive-cycle, reductions in CO, NOx and particle number were observed, but a higher total PM mass was recorded. 相似文献
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针对广汽自主品牌"传祺"轿车的底盘铝合金后副车架压铸零件,从压铸合金的力学性能、压铸工艺设计及优化、模具设计及制造、铸件质量控制等方面进行了开发和研究。结果表明,采用耐热密封结构的高真空压铸模具具有良好的密封性能,可靠性高。多区域的温度测量及冷却水流量的实时调节提高了模具温度控制的精度。通过对工艺参数的优化,有效消除了铸件缺陷如裂纹、冷隔、缩孔、缩松等。开发的铝合金后副车架的铸件本体抗拉强度≥240MPa,屈服强度≥145MPa,伸长率≥6%,满足了"传祺"轿车的的使用要求。 相似文献