Motor drive apparatus for electric forklift and electric forklift adopting the same

摘要

A motor drive apparatus of an electric forklift includes first and second torque command value generation units that individually generate a torque command value indicating torque of a corresponding traveling motor in response to a gap between a speed command value and a speed detection value; and first and second slip detectors that individually generate a slip ratio estimation value showing a slip state of a corresponding drive wheel based on the speed detection value and the torque command value. The slip detectors individually have a first arithmetic unit which generates an inertial force estimation value proportional to a differential value of the speed detection value of the corresponding traveling motor and a second arithmetic unit which generates the slip ratio estimation value in response to a relationship between the corresponding inertial force estimation value and the torque command value of the corresponding traveling motor.

主权项

1. A motor drive apparatus of an electric forklift which is mounted on the electric forklift and controls a first traveling motor and a second traveling motor, respectively transmitting power to a left drive wheel and a right drive wheel of the electric forklift based on a speed command value showing a target speed of the electric forklift, the apparatus comprising:
a first torque command value generation unit and a second torque command value generation unit that are respectively provided in the first traveling motor and the second traveling motor, each of which generates a torque command value indicating torque of the corresponding traveling motor in response to a gap between a speed command value of the corresponding traveling motor and a speed detection value that is a current speed of the corresponding traveling motor; and a first slip detector and a second slip detector that are respectively provided in the first traveling motor and the second traveling motor, each of which generates a slip ratio estimation value showing a slip state of the corresponding drive wheel based on the speed detection value of the corresponding traveling motor and the torque command value of the corresponding traveling motor, wherein each of the first slip detector and the second slip detector includes a first arithmetic unit which generates an inertial force estimation value proportional to a differential value of the speed detection value of the corresponding traveling motor and a second arithmetic unit which generates the slip ratio estimation value in response to a relationship between the corresponding inertial force estimation value and the torque command value of the corresponding traveling motor.