LIFTING AND LOWERING CONTROL DEVICE FOR SEEDLING PLANTING DEVICE OF RICE TRANSPLANTER

摘要

PURPOSE: To provide the lifting and lowering control device capable of reinforcing ground making function and avoiding mistaken control by false detection of a furrow trace depth detecting means by shifting control sensitivity of lifting and lowering control to an insensitive side when the control value of a furrow trace sensor extremely exceeds an ordinary detected value. ;CONSTITUTION: A seedling planting device is drivably and liftably connected to a traveling machine body. This lifting and lowering control device is equipped with a right and a left furrow trace sensors T for measuring depth of a right and left ground making floats 17S sunk in a field arranged behind driving wheels based on the furrow trace depth of the ground making floats 17S, a center float for lifting and lowering the seedling planting device based on variation of grounding pressure and a lifting and lowering detecting means for discovering the amount of the center float lifted or lowered, a control means which transfers control sensitivity to a sensitive side with increase in the average value of the measured results of the furrow trace sensors T and shifts the control sensitivity to an insensitive side by a controlling means when a control value based on the measured results of at least one furrow trace sensor T is a large value exceeding an ordinary detected value and occurring at an almost certain period.;COPYRIGHT: (C)1996,JPO