| For a long time,at transmission has a considerable share in the automatic transmission market,especially in our country,where most of the at transmissions of the domestic main engine factory are imported.At automatic transmission technology has been dominated by foreign investment,and formed a patent family for protection.In 2010,domestic enterprises have successfully developed the 8at transmission,marking that China has fully independent intellectual property rights of multi gear hydraulic automatic transmission.turning the "strongest automotive brain" of 8at from a concept to a technical product.Due to the slow start,inexperience,technica 1 barriers and other factors,there is a gap between China's 8at technology and foreign countrie s,so it is of great significance to study the shift law of high-end 8attransmission.This paper mainly introduces the research status of at transmission at home and abroad,on the basis of which the core of this paper is determined.First of all.using the lever method to analyze the power transmission of Bat transmission structure in gear 1-8 and reverse,and make the equivalent lever diagram,and calculate the transmission ratio of each gear.Then the mathematical principle of the vehicle dynamic model is calculated according to the vehicle theory,and the vehicle dynamic simulation model matching 8at is built on this basis.Secondly,the running speed,power factor,climbing angle and maximum speed of each gear of automatic transmission are calculated.Finally,the dynamic simulation model of the whole vehicle is established according to the two parameter shift law and the shift curve.According to the model,the change process of throttle opening,vehicle speed and engine speed at different shift points is obtained,and the power transmission process of 8AT is simulated truly and reliably.The research of this paper lays a solid foundation for the research of matching 8-speed hydraulic automatic transmission vehicle,and has an important guiding significance. |
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