Vehicle drive system

摘要

A vehicle drive system includes a transmission, a clutch, and a shift execution portion. The shift execution portion operates the shift actuator to control the connecting portion in an engaged state engaged with the idler gear of a present gear stage to disengage from the idler gear of the present gear stage while gradually decreasing the engine torque while the clutch is still engaged, when a shift operation from the present gear stage to a subsequent gear stage is executed.

主权项

1. A vehicle drive system comprising:
a transmission including
an input shaft receiving an engine torque,an output shaft arranged in parallel with the input shaft, the output shaft configured to rotatably connect to a driving wheel,plural idler gears idly rotatably arranged at one of the input shaft and the output shaft,plural fixed gears fixed to the other of the input shaft and the output shaft so as not to relatively rotate, the plural fixed gears being engageable with the plural idler gears, respectively,a connecting portion provided at a first shaft, from among the input shaft and the output shaft, at which the plural idler gears are arranged, and positioned side by side with the plural idler gears so as not to rotate relative to the first shaft and so as to move in an axial direction of the first shaft, the connecting portion for rotatably connecting a first idler gear from among the plural idler gears and the first shaft so as to restrain the first idler gear and the first shaft from rotating relative to each other, anda shift actuator moving the connecting portion in the axial direction to engage the connecting portion with the first idler gear so as not to relatively rotate, the shift actuator moving the connecting portion in the axial direction to be disengaged from the first idler gear so as to relatively rotate; a clutch configured to be arranged between a drive shaft receiving the engine torque and the input shaft, the clutch selectively connecting the drive shaft and the input shaft; and a shift execution portion operating the shift actuator to control the connecting portion in an engaged state engaged with the idler gear of a present gear stage to disengage from the idler gear of the present gear stage while decreasing the engine torque at a substantially constant first rate while the clutch is still engaged, across a first period between a first time when a shift operation from the present gear stage to a subsequent gear stage is executed and a second time when a driving of the shift actuator in a direction toward a neutral position at which the connecting portion is disengaged from the plurality of idler gears is started, wherein the shift execution portion, after decreasing the engine torque to a reference torque during the first period, at the second time operates the shift actuator to control the connecting portion in the engaged state engaged with the idler gear of the present gear stage to disengage from the idler gear of the present gear stage by operating the shift actuator while decreasing the engine torque at a substantially constant second rate across a second period between the second time and a third time at which the shift actuator is brought into a neutral position, and wherein the shift execution portion memorizes the engine torque at a time when movement of the connecting portion is detected as a learned torque and calculates the reference torque based on the learned torque when disengaging the connecting portion in the engaged state engaged with the idler gear of the present gear stage to disengage from the idler gear of the present gear stage.