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前言柴油机直喷式燃烧室采用螺旋进气道以产生空气涡流来组织燃烧,因而表征空气涡流运动的特性参数对柴油机的动力经济性指标影响很大。但螺旋进气道形状复杂,不易用一些结构尺寸参量来表达。螺旋进气道的设计一般先用石膏作气道模型,在气道涡流试验台上根据测量结果反复修改,而后通过柴油机性能试验验证,才能最后确定。由于石膏强度很低,设计出来的进气道石膏芯盒不能直接用于试生产。按常规工艺要用石膏模翻制成铸铝、铸铁、塑料的芯盒,由于这些材料制的芯盒其变形收缩大,工艺过程复杂,很难保证气道的设计特性参数,有的只好报废,而且制造周期长。
Introduction Diesel direct injection combustion chamber using spiral inlet to generate air swirl to organize combustion, and thus characterize the characteristics of air swirl movement of diesel engine power economic indicators of great influence. However, the shape of the spiral inlet is complex and difficult to express with some structural dimension parameters. The design of the spiral inlet is generally first used gypsum as the airway model, in the airway vortex test bench according to the measurement results repeatedly modified, and then through the diesel engine performance test verification, to finalize. Due to the low gypsum strength, the designed inlet gypsum core box can not be directly used for trial production. According to the conventional process, plaster molds are used to turn cast aluminum, cast iron and plastic core boxes. Since the core boxes made of these materials have large deformations and shrinkages and complicated technological processes, it is difficult to ensure the design parameters of the airways, and some of them have to be scrapped , But also long manufacturing cycle.