APPARATUS FOR AUTOMATIC CONTROL OF FLOAT GROUNDING PRESSURE AND COVERED SOIL PRESSURE OF DIRECT SOWING VEHICLE FOR FLOODED PADDY FIELD

摘要

PURPOSE:To adjust the grounding pressure and the covered soil pressure to optimum levels according to the hardness of the soil, by controlling a float and a soil-covering tool according to the relative angular displacement between a grounding member and a detector to detect the hardness of soil and to the vertical oscillation displacement of the float and the soil-covering tool. CONSTITUTION:When the soil of a paddy field is hard, the depth of a detector 51 thrust into soil becomes shallow to cause a relative angular displacement between the detector 21 and the grounding member 49. The float 21 and the soil-covering tool 23 tend to rise. The angular displacement between both members is detected with angle sensors 53, 80, the actuator 76 is extended to loosen the strips 36, 37 and the float 21 and the soil-covering tool 23 are pressed against ground by the spring force of springs 30, 33 to apply a float grounding pressure and soil-covering pressure adjusted according to the hardness of the soil. When the soil of the paddy field is soft, the flat 21 and the soil- covering tool 23 are raised in the similar manner to decrease the spring force of the springs 30, 33.