Abstract: With the continuous development of production technology, the vehicle manufacturing industry has put forward higher requirements for the test means of air conditioning system, and the positive pressure leak test has been applied in more and more vehicle enterprises, but the leak test media are diverse, and there is no unified reference standard for the selection of leak test media. This paper takes helium, nitrogen and compressed air, three leak test media mainly used by automobile enterprises, as the research object, through the analysis method combining theory and practice, aims to improve the efficiency of the selection of positive pressure leak test media in the air-conditioning system of each vehicle enterprise, and reduce the production cost. In this paper, from comprehensive comparative analysis of five aspects, such as the principle of positive pressure leak test, the application of positive pressure leak test media, test specifications, test equipment capacity and leak test cost, finds out the advantages and disadvantages of different leak test technology, to provide reference for the medium selection of vehicles and enterprises and derives optimal conclusions.

Key words: Positive pressure leak test; Medium selection; Reducing cost; Cycle time; Air conditioning system

摘要： 随着生产技术的不断发展进步，整车制造业对空调系统检测手段提出了更高的要求， 而正压检漏也在越来越多的整车企业中得到了应用，但检漏介质多样，各车企对于检漏介质 选型无统一参考标准。以车企主要应用的三种检漏介质氦气、氮气、压缩空气为研究对象， 通过理论与实际相结合的分析方法，旨在提高各整车企业在空调系统正压检漏介质选型的效 率，同时降低生产成本。从正压检漏原理、正压检漏介质应用、检测规范、检测设备能力和 检漏成本五个方面进行综合对比分析，找出不同检漏工艺的优缺点，为各车企介质选型提供 参照并得出最优结论。

关键词: 正压检漏；介质选型；降低成本；周期时间；汽车空调系统