HEIGHT DETECTOR OF FORK LIFT AND FORK LIFT

摘要

PROBLEM TO BE SOLVED: To provide a height detector capable of detecting a body to be detected repeatedly and completely over a long period without touching it. SOLUTION: An ultrasonic detector 15 is mounted on the outer surface 11o of an outer mast 11. A detecting part 17 is fitted into a detection hole 19 formed in the outer mast 11R, and a signal sending and receiving surface 18 is made to face an outer surface 12o of an inner mast 12R. A signal processing part ultrasonically-oscillates the ultrasonic oscillator of an ultrasonic sensor at every prescribed detection cycle for a prescribed oscillation time and generates a detected signal from the received signal which occurs at an ultrasonic oscillator by a reflected wave. When the detected signal is inputted within a detecting time between the point at which the prescribed stand-by time elapses after the oscillation time ends and the end of the detection cycle, a micro computer discriminates the inner mast 12R as being detected.