目前,发动机的修理大量是换件修理,因此装配问题显得特别重要。为了保证发动机的装配质量,除应掌握装配的一般工艺和技术要求外,本文提出以下值得注意的几个技术问题。 (1)装配用的零部件都要进行技术鉴定,特别要注意对新件的检查。合格后,方可装配。这是因为,新的零部件在出厂后几经碾转,加上包装、存放、防护不当,往往产生变形、锈蚀甚至裂痕。除此之外,有些零件还要考虑材料的差异,如铝活塞、曲轴瓦等,因为成分不一样,膨胀系数亦不一样,故在决定配合间隙时,应有不同的数值。譬如铝活塞,装配前可用开水加热,测其膨胀量,以便决定它同气缸的配合间隙。 (2)要注意零部件的清洁。零部件在拆检时虽经清洗,但此后还要经过加工、运送、存放等过程,往往被重新脏污。因此,装配时要重新检查和清洗零部 At present, a large number of engine repair is a replacement repair, so the assembly problem is particularly important. In order to ensure the assembly quality of the engine, in addition to the general assembly and assembly technology and technical requirements, the paper presents the following several technical issues worth noting. (1) assembly of parts and components must carry out technical appraisal, with particular attention to the inspection of new pieces. After passing, before assembly. This is because, after the new parts and components have been grinded by the factory, with packaging, storage, improper protection, often produce deformation, rust and even cracks. In addition, some parts should also consider the material differences, such as aluminum piston, crank bearing, etc., because the composition is not the same, the expansion coefficient is not the same, so in the decision with the gap, there should be different values. For example, aluminum piston, boiled water can be used before assembly heating, measuring its expansion, in order to determine its cooperation with the cylinder clearance. (2) pay attention to the cleaning of parts. Although the parts were dismantled while cleaning, but after going through the processing, transportation, storage and other processes, are often re-dirty. Therefore, the assembly should be re-checked and cleaned parts