| 摘要 |
<p>PURPOSE: To raise lubricating property for a deceleration rotation mechanism in selecting a low speed position through a sub-transmission by setting a control fluid at low pressure, and causing a frictional clutch to generate an initial clutch tightening force for keeping a wet multiple disc clutch in a slightly engaged state, upon the selection of the position. CONSTITUTION: A driving power transmission system of an FR type parttime four-wheel drive vehicle has a transfer for dividing driving power from a transmission for distribution to front and rear wheels, and a sub-transmission mechanism 58 is laid between an input shaft 42 and an output shaft 44. Also, a two- wheel and four-wheel drive selector mechanism 60 is provided between the output shaft 44 and another output shaft 54. The mechanism 60 is provided with a frictional clutch 66 for changing a driving power distribution ratio for the front and rear wheels. Also, when a sub-transmission lever is selected at a low speed shift position for controlling the clutch 66, initial torque is calculated on the basis of a detected oil temperature value, and this initial torque is set as transmission torque for the front wheels to calculate clutch pressure.</p> |
