Split-crankshaft engine: concept for a combustion engine with a two-piece disengageable crankshaft
Split-crankshaft engine: concept for a combustion engine with a two-piece disengageable crankshaft
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分体式曲轴发动机：带有两件式可分离曲轴的内燃机概念
DOI：
10.1007/978-3-658-05130-3_68
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Pflaum
中科院分区：
文献类型：
--
作者：
Bergmaier;Wachtmeister;Fischer;Pflaum
对于最近开发的几乎每一台新发动机来说，缩小尺寸都已成为最先进的技术。它提供了更好的燃油消耗，并可以减轻重量，这又一次增加了效率效益。这些发动机的气缸单元在非常宽的负载范围内运行。因此，必须将更多的技术特征集成到发动机中，以补偿负载响应的滞后或抵消增加的热应力和机械应力。发动机使用的小型化程度决定了在常见的低负荷驾驶循环中可能节省的燃料，但随着可能的收益增加，技术复杂性也随之增加。为了避免这些相互冲突的目标，几家汽车制造商已经采取了积极的裁员措施。它允许常规发动机停用一定数量的气缸，从而利用剩余气缸的更高负荷和更好的比油耗。在本出版物中，提出了一种更广泛的主动缩小尺寸的方法。拟议的发动机概念的主要特点是通过停用非工作气缸的机械部件来减少摩擦损失。同时，特别强调非常低的技术复杂性，以降低可能生产的成本。这是通过将发动机分成两个自主单元并根据其各自的需求进行设计实现的，这些需求不仅涉及几何形状，还涉及燃烧过程，特别是充电。循环模拟显示，尽管所开发的部分发动机没有采用可变系统，并在整个运行图中使用化学计量空燃比，但在不同的驾驶循环中，燃料消耗的改善幅度从4%到14%。
Downsizing has become state of the art for almost every new engine recently developed. It offers improved fuel consumption and can reduce weight which, again, increases efficiency benefits. The cylinder units of those engines operate in a very wide range of loads. Therefore an increased number of technical features have to be integrated into the engines to compensate for the lag in load response or to counteract increased thermal and mechanical stress. The level of downsizing utilized by an engine determines potential fuel savings in common low-load driving cycles, but, as the possible gains rise, so does the technical complexity. To avoid those conflicting objectives active downsizing has been introduced by several automotive manufacturers. It allows regular engines to deactivate a certain number of cylinders and therefore take advantage of the higher loads and better specific fuel consumption of the remaining ones.In the present publication a more extensive approach to active downsizing is presented. The key feature of the proposed engine concept is the reduction of friction losses by deactivating the mechanical parts of the non-operating cylinders. At the same time a very low level of technical complexity is particularly emphasized to reduce costs of a probable production. This is achieved by splitting the engine into two autonomous units and designing each of those to its individual demands, not only concerning geometry but also combustion process and particularly charging. Cycle simulations show improvements in fuel consumption reaching from 4% to 14% for various driving cycles, although the developed part engines incorporate no variable systems and utilize a stoichiometric air-fuel ratio throughout the whole operation map.