| 摘要 |
PROBLEM TO BE SOLVED: To perform forward and reverse drive of left and right front wheels properly corresponding to the steered angle of a wheel to be steered, without providing a steered angle sensor which detects the steered angle (steered tire angle) of the wheel to be steered. SOLUTION: The left and right front wheels unsteerable of a forklift are driven by independent driving motors 4L, 4R respectively, and its one rear wheel is one to be steered. Currents flowing in the driving motors 4L, 4R are detected by current sensors 24L, 24R, and their output signals are inputted to a microcomputer 17 through A/D converters. On the basis of data representing the relation between a steered angle stored in a memory 25 and a current flowing in each of both motors 4L, 4R, the microcomputer 17 estimates the steered angle of the rear wheel. Contactors for forward rotation 6F, 7F and contactors for reverse rotation 6R, 7R are switched to proper states corresponding to the steered angle, and forward and reverse rotation or the driving motors 4L, 4R is controlled. |
