A method for achieve synchronous range shifting in an electronically controlled two-stage power take-off gear with an electronically controlled motor and transmission

摘要

A method for shifting a two-stage transfer case between a low speed range and a high rotational speed range in a four wheel drive type comprises the determining a target transmission via composition ratio and a desired distributor gear unit area on the basis of the current vehicle speed and the initial distributor transmission region. The gear mechanism is at the target composition ratio is connected via a transmission, if it is determined that the speed of the vehicle in a suitable range. The distributor gear drive torque is reduced to a minimum value and the dividing transmission is switched over to idle. The method comprises the further adjustment of the engine rpm and the transmission gear setting, in order to allow the transmission output shafts speed to a desired range control. The dividing transmission is from idling to the desired distributor transmission region, if the transmission power take-off shaft rotational speed within the desired region of the transmission output shafts speed lies.