MOTOR CONTROL APPARATUS

摘要

A motor control apparatus for adjusting a cam phase includes a motor control part, which controls a current supplied to a stator coil by controlling plural switching elements forming an inverter to turn on and off. The motor control part stops the current supplied to the stator coil each time a motor rotates a predetermined rotation angle interval in a power generation control mode, in which a rotation torque is generated in a direction to impede the motor rotation. The motor control part maintains the power generation control mode when a rotation signal is determined as varying in a predetermined time period. The motor control part switches over an operation mode to a normal control mode to generate a rotation torque in a direction to promote the motor rotation when the rotation signal is determined as not varying in the predetermined time period.

主权项

1. A motor control apparatus for controlling driving of a motor, which is coupled mechanically to a crankshaft and a camshaft of an internal combustion engine through a valve timing conversion unit to adjust a phase of the camshaft relative to the crankshaft, the motor including an output shaft coupled to the valve timing conversion unit, a rotor fixed to the output shaft and having permanent magnets, and a stator provided around the rotor and having a stator coil, the motor control apparatus comprising:
an inverter including plural switching elements for supplying a current to the stator coil to generate magnetic fluxes, which exert on the permanent magnets to generate a rotation torque in the rotor in a direction to promote or impede rotation of the output shaft; a rotation angle detection part for generating a rotation signal varying with a rotation angle of the motor and a rotation direction of the motor; a motor control part for controlling the plural switching elements of the inverter to turn on and off based on the rotation signal thereby to control the current flowing in the stator coil and control generation of the rotation torque; and a command part for commanding the motor control part to increase and decrease, wherein the motor control part is configured to operate in a normal control mode when the rotation torque is commanded to promote the rotation of the motor, and a power generation control mode when the rotation torque is commanded to impede the rotation of the motor, the motor control part is configured to supply the current to the stator coil always irrespective of the rotation angle of the motor in the normal control mode, and stop the current from being supplied to the stator coil at every rotation of the motor over a predetermined rotation angular interval in the power generation control mode, and the motor control part is configured to check whether the rotation signal varies in a predetermined time period in the power generation control mode, maintains the power generation control mode upon determination that the rotation signal varies in the predetermined time period, and switches over the operation mode to the normal control mode upon determination that the rotation signal does not vary in the predetermined time period.