Patent Document ID: 9806664
Application ID: 13947567
Patent Flag: 1

Claim One:
1. A range switchover apparatus comprising: a range switchover mechanism having a motor as a drive source for switching over a shift range among plural ranges; a detent mechanism for holding the range switchover mechanism at each range position; an encoder for outputting a pulse signal in synchronism with rotation of the motor; and a control unit for executing an initial driving operation, in which power supply phases of the motor is switched over by open-loop control after electric power is turned on, and performing initial learning processing, which learns a phase deviation correction value corresponding to a phase deviation of a power supply phase relative to an encoder count value indicating a count value of the pulse signal of the encoder; wherein: in a normal driving operation following the initial learning processing, the encoder count value is corrected by the phase deviation correction value, and the motor is rotationally driven by sequentially switching over the power supply phases in accordance with a corrected encoder count value; the control unit rotates the motor first in a predetermined direction corresponding to a restraint caused by a shape of the detent mechanism in performing the initial learning processing, the predetermined direction ensuring the detent mechanism to hold the range switchover mechanism at a predetermined range position more surely than other direction; the range switchover apparatus further comprises a limitation member for limiting a movable range of the detent mechanism; and the control unit sets the predetermined direction of the motor to move the detent mechanism in a direction away from the limitation member in executing the initial driving operation so that the detent mechanism does not contact the limitation member; and said other direction is a direction toward the limitation member.