Patent ID: 9630492
Date: 2017-04-25
CPC Classifications: B60K,F16D

Claim:
1. A four-wheel drive vehicle that enables switching between a four-wheel drive state where a driving force of a driving source is transmitted to a pair of right and left main driving wheels and a pair of right and left auxiliary driving wheels and a two-wheel drive state where the driving force of the driving source is transmitted only to the main driving wheels, the four-wheel drive vehicle comprising: a propeller shaft that transmits the driving force of the driving source to the auxiliary driving wheels in the four-wheel drive state; a transmission and cut-off mechanism that cuts off transmission of the driving force from the driving source to the propeller shaft in the two-wheel drive state and that enables transmission of the driving force from the driving source to the propeller shaft in the four-wheel drive state; a driving shaft that rotates under a turning force of the propeller shaft and that has a central axis extending in a vehicle width direction; a pair of hydraulic clutches each disposed between the driving shaft and a corresponding one of the auxiliary driving wheels and having a plurality of clutch plates that enable the driving force to be frictionally transmitted; a hydraulic unit that supplies hydraulic oil to the hydraulic clutches and that brings the clutch plates into frictional contact with one another using the hydraulic oil; and a control apparatus that controls the hydraulic unit, wherein, in shifting the two-wheel drive state to the four-wheel drive state, the control apparatus supplies the hydraulic oil to a first hydraulic clutch of the pair of hydraulic clutches and subsequently supplies the hydraulic oil to a second hydraulic clutch of the pair of hydraulic clutches.