Research On The Computer Aided Parts Assembly For Soil-free Scroll Air Compressor

Computer aided selective assembly is a way of making use of computer and valid arithmetic to arrange the component link size of assembly size chain reasonably. In this way, the parts produced according to the normal production conditions can be assembled precisely, so that the changing range of closing link deviation can be reduced, the product quality can be improved, and the production cost can also be reduced.In terms of multiple dimensional chain assembly, the existing research often adopt the method of weighting and multiple dimension chain can be converted to single dimension chain. Using weighting method, the calculation process is simple. However, When there is a cross between dimension chains, the objective function will dominate each other, which can’t be solved by weighting method. Only the multi-objective optimization algorithm is capable of working out this problem. Scroll compressor assembly is a kind of this problem. The assembly quality of a scroll compressor is mainly depend on the scroll plate assembly space. The assembly target is to meet the axial and radial clearance requirements, in addition, the remaining parts should be minimum.In this paper, a type of oil-free scroll air compressor assembly was researched. Center on multi-objective parts selection with multiple parameters and lot sizing, researches were carrying out into the optimization matching method. First of all, the structure, working principle, performance requirements, influencing factors of assembly precision were studied, and assembly dimensional chains were worked out. Secondly, according to the assembly targets, the matching objective function was determined, multi-objective selective assembly mathematical model was established. Thirdly, non-dominated sorting genetic algorithm-II(NSGA-II) was used to solve this assembly mathematical model, and the algorithm process was designed in detail. Finally, selective assembly algorithm was realized on the ASP.NET platform, and the example of06A scroll plate selective assembly verified the practicality and superiority of NSGA-II.