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为了实现较好的动力和环保性能,开发了1种小型化1.5L涡轮增压发动机。该发动机旨在替代1.8~2.4L的自然吸气发动机。在小型化涡轮增压发动机中,混合气均匀性对抑制爆燃和减排十分重要。特别是在发动机高负荷运行时,创造快速燃烧和均匀混合气是关键的技术。采用了长行程直喷发动机作为满足这些要求的基本机型,它具有显著的快速燃烧能力和较高的热效率。将长行程与高滚流气道和支持滚流的浅盆形活塞相结合,增强了混合气在气缸内的流动。建立的燃烧系统包含1个能减少爆燃的充钠排气门和1个有利于形成均匀混合气和减少燃油湿壁的多孔(6孔)喷射器。依靠快速燃烧,能够实现很高的缸内压力,因而能提高平均指示有效压力,即使在转速1500r/min全负荷下推迟点火正时的情况下也是如此。双气门正时控制(VTC)有可能为不同的发动机转速和负荷设定最佳的进排气门重叠角和气门正时。VTC与上述燃烧系统相结合实现了220g/(kW·h)~(-1)的最低比油耗和38%的最大热效率。还介绍了发动机的动力输出性能和燃油经济性,以及为达到低排放、减少振动和噪声、实现轻量化和整车性能采用的技术。
In order to achieve better power and environmental performance, developed a miniaturized 1.5L turbocharged engine. The engine is designed to replace 1.8 ~ 2.4L naturally aspirated engine. In miniaturized turbocharged engines, the uniformity of the mixture is important to suppress deflagration and reduce emissions. Especially when the engine is under high-load operation, it is the key technology to create a fast combustion and a homogeneous mixture. Long-stroke direct injection engines are used as a basic model to meet these requirements, with significant rapid combustion capability and high thermal efficiency. The combination of a long stroke with a high tumble airway and a shallow basin-shaped piston that supports tumble flow enhances the flow of the mixture within the cylinder. The combustion system was built to include a sodium deflation valve to reduce deflagration and a porous (6-hole) injector to create a homogeneous mixture and reduce the wet wall of the fuel. Rely on rapid combustion to achieve high in-cylinder pressure, thereby increasing the mean indicated effective pressure, even with retarding of the ignition timing at a full load of 1500 rpm. Dual Valve Timing Control (VTC) It is possible to set the optimum intake and exhaust valve overlap angle and valve timing for different engine speeds and loads. In combination with the above combustion system, VTC achieves the lowest specific fuel consumption of 220 g / (kW · h) -1 and the maximum thermal efficiency of 38%. The engine’s power output and fuel economy are also described, as well as techniques used to achieve low emissions, vibration and noise reduction, weight reduction and vehicle performance.