Power steering apparatus

A power steering apparatus with a power steering function to drive an oil pump by a motor to generate hydraulic pressure, and to assist in driver's steering through the hydraulic pressure, the power steering apparatus comprising:

• a power source voltage detecting means which detects the voltage of a power source of the power steering apparatus;
• a motor rotating speed detecting means which detects the rotating speed of the motor;
• and
• a control stopping means which recognizes that the voltage of the power source is in a normal range when the voltage of the power source detected by the power source voltage detecting means exceeds the predetermined power source voltage value, and recognizes that the voltage of the power source is in a decrease state range when the voltage of the power source is equal to or less than the predetermined power source voltage value;
• recognizes that the motor rotating speed is in a normal range when the rotating speed of the motor detected by the motor rotating speed detecting means exceeds the predetermined motor rotating speed value, and recognizes that the motor rotating speed is in a decrease state range when the rotating speed of the motor is equal to or less than the predetermined motor rotating speed value;
• determines that the power steering apparatus fails when it is recognized that the power source voltage is in the normal range, and the motor rotating speed is in the decrease state range;
• and stops the power steering function when the determination lasts for a predetermined time.