在直喷式柴油机中,减小深盆形燃烧室的顶隙可以确保好的性能和排烟。为了说明这点在单缸柴油机上用不同顶隙值做试验,结果表明,顶隙减小可得到低的烟度,而且在某一顶隙下可得到最好的经济性。这证明小的顶隙使凹坑的混合气在燃烧初期流入顶隙中的较少。 In direct injection diesel engines, reducing the head space of the deep basin-shaped combustion chamber ensures good performance and smoke exhaust. To illustrate this point, experiments with different headspace values ​​on a single cylinder diesel engine showed that reducing the head space resulted in low smoke levels and the best economy was achieved with a headspace. This proves that the small head space makes the mixture of the dimples less likely to flow into the headspace at the beginning of combustion.