Vehicle parking lock system

A vehicle parking lock system comprising:

• an input shaft to which a torque is input from a drive source mounted on a vehicle;
• an output shaft outputting the torque input from the input shaft via a transmission to a drive wheel of the vehicle;
• and
• a parking lock mechanism adapted to restrict either a rotation of the input shaft or a rotation of the output shaft,
• the parking lock mechanism including a selectable clutch provided to one of the input shaft, the output shaft, and an intermediate shaft in the transmission, a plurality of sensors mounted on the vehicle, and a control unit,
• the selectable clutch including a fixed race and a rotating race that are arranged coaxially, and being configured to be switchable between four operating modes including:
• a two-way lock mode prohibiting rotation of the rotating race relative to the fixed race in both forward and reverse directions;
• a forward lock mode prohibiting rotation of the rotating race relative to the fixed race in the forward direction;
• a reverse lock mode prohibiting rotation of the rotating race relative to the fixed race in the reverse direction;
• and
• a two-way free mode allowing rotation of the rotating race relative to the fixed race in both forward and reverse directions,
• the plurality of sensors including:
• a first sensor that detects whether or not the vehicle is in a drivable state, when the vehicle is stationary;
• a second sensor that detects whether or not the vehicle continues to be stationary;
• and
• a third sensor that detects an inclination of the vehicle,
• the control unit being adapted to control the operating modes of the selectable clutch based on detection signals of the plurality of sensors to prevent an unintended movement of the vehicle when the vehicle is stationary.