关键词: 轻型商用车；电控机械式自动变速箱；换挡系统；耐久性能指标；Cruise

Abstract: Automatic transmission commercial vehicles, especially logistics vehicles mainly carried in urban areas, put forward the higher durability requirement for the shift system of automatic transmission because of their complex operating conditions, low average driving speed and frequent starting and shifting. Therefore, it is necessary to set a reasonable durability index for the shift system at the early stage of automatic transmission product design and development, then carry out design, development and test verification based on the durability target, so as to ensure the reliability of the transmission shift system from the design source. This paper investigated the actual application road conditions of a commercial logistics vehicle put into Hefei area, analyzed and screened the representative urban and suburban road conditions, tracked and collected a large number of road condition data, used the Cruise software for simulation calculation and statistical analysis, and finally calculated the cumulative shift times and shift times of each gear based on the life goal according to the proportion of each road condition and load proportion of the target vehicle, which could provide a theoretical basis for the setting of durability index of shift system.

Key words: Light commercial vehicle; Automatic mechanical transmission; Shift system; Durability index; Cruise