Patent ID: 6962226

Claim:
A vehicular two-wheel drive and four-wheel drive switching system, comprising: a switching unit provided on either side of power transmission mechanisms, respectively, provided between an engine and front wheels and between the engine and rear wheels for transmitting power in the power transmission mechanism or disconnecting the transmission of power; a driving shaft connected to a drive side; a driven shaft fitted to the driving shaft via an annular clearance gap, said driving shaft and said driven shaft being concentrically arranged relative to each other; a plurality of connecting/disconnecting members provided coaxially and extending a predetermined distance coaxially along the driven shaft in a clearance between the driving shaft and the driven shaft for connecting or disconnecting the driving shaft and the driven shaft by being fitted or disconnected to/from the respective opposite surfaces; a switching mechanism for selectively positioning the connecting/disconnecting members in a position in which the driving shaft and the driven shaft are connected and in a position in which they are disconnected; and a control unit for controlling the drive of the switching mechanism, said control unit supplies driving current to the switching mechanism by repeating continuous supply and supply by duty cycle control, wherein a reverse speed predetermined value is utilized when operating a vehicle in reverse.