PURPOSE: To blow off grass in a chuter and prevent clogging by providing a transmitting type photosensor in the chuter and sensing the density of the grass transferred in the chuter based on its output signal.
CONSTITUTION: A transmitting type photosensor 40 is provided in a chuter 13 and the density of grass transferred in the chuter 31 is sensed based on its output signal. A high-level sensed signal of a signal outputted at a predetermined interval from a sensing part 28 is counted with a counter 29 and the light shielding ratio is calculated based on the counter value with a calculating part 30. The relationship of magnitude between the threshold value and the light shielding ratio is judged. If the light shielding ratio is larger, it is judged that there is a fear of causing clogging. A solenoid 27 is then turned ON to forcedly change over a speed changer 33 to a neutral position. The travel of a reaper is rapidly decelerated while keeping the rotation of a cutter as it is. As a result, the grass in the chuter is blown off to prevent clogging.
NOMICHI AKIO
SHIMADA TADASHI
NAKAMURA TOSHIKAZU
