Four-wheel drive vehicle clutch control method and clutch control device

A four-wheel-drive vehicle clutch control device for a four-wheel-drive vehicle in which either left and right front wheels or left and right rear wheels are configured as main drive wheels connected to a drive source, and the other of the left and right front wheels or the left and right rear wheels are configured as auxiliary drive wheels connected via a friction clutch to the drive source, and the four-wheel-drive vehicle clutch control device comprising:

• a 4WD controller programmed to engage the friction clutch when the vehicle starts off due to an accelerator depressing operation, whereby drive torque from the drive source is distributed to the main drive wheels and the auxiliary drive wheels,
• the 4WD controller being further programmed to perform a control to apply an initial torque as an engagement torque control of the friction clutch when the vehicle is stopped after the vehicle has changed over from a traveling state to a stopped state while remaining in a travel shift position;
• and
• the 4WD controller being further programmed to set a magnitude of the initial torque to a magnitude that is necessary for maintaining a drive-system torsion state by torque transmitted to an auxiliary-drive-wheel drive system before the vehicle is stopped.