Indicating instrument for vehicle

摘要

An indicator indicates a vehicle state value in accordance with a rotational position between a zero position and a maximum position. A step motor rotationally drives the indicator on application of a drive signal in accordance with an electrical angle to a field winding. A control unit that controls the electrical angle of the drive signal applied to the field winding performs a leave-zero control operation which varies the electrical angle to rotate the indicator from the zero position to the maximum position and determines presence or absence of abnormal rotation of the indicator based on the electrical angle at the time of detecting the stopping of the indicator during the leave-zero control operation.

主权项

1. An indicating instrument for a vehicle, comprising:
an indicator that indicates a vehicle state value in accordance with a rotational position between a zero position and a maximum position; a step motor that has a field winding and rotationally drives the indicator on application of a drive signal in accordance with an electrical angle to the field winding; a control device that controls the electrical angle of the drive signal applied to the field winding and performs a leave-zero control operation which varies the electrical angle so as to rotate the indicator from the zero position toward the maximum position; a detection device that detects stopping of the indicator; and a determination device that determines presence or absence of abnormal rotation of the indicator on the basis of the electrical angle when the detection device has detected the stopping of the indicator during the leave-zero control operation; wherein the electrical angle when the indicator has been rotated to the zero position is defined as a zero angle, the electrical angle when the indicator has been rotated to the maximum position is defined as a maximum angle, and the electrical angle when the detection device has detected the stopping of the indicator during the leave-zero control operation is defined as a leave-zero-operation-stop detection angle, and wherein, on determining that an angle difference between the zero angle and the leave-zero-operation-stop detection angle has not reached an angle difference between the zero angle and the maximum angle, the determination device determines the presence of the abnormal rotation.