WORKING MACHINE LIFT CONTROL DEVICE OF TRACTOR

摘要

PROBLEM TO BE SOLVED: To eliminate a phenomenon that a lift arm is lifted by itself due to a leak or the like of hydraulic pressure when a working device travels while being released from the lift arm, in a working machine lift control device of a tractor which lifts up the working machine attached to the tractor by using a lift operation implement.;SOLUTION: In a working machine lift control device of a tractor which lifts a working machine 2 attached to the tractor by driving a lift arm 17 by the operation of a lift operation implement 5, when a set height of the lift operation implement 5 is different from a height of the working machine 2 at powering-on or at the start of an engine 34, and when a height of the lift arm 17 is different from the set height of the lift operation implement 5 at the powering-on or at the start of the engine 34, and also when it is detected that the working machine is not attached to the lift arm 17, the lift operation of the lift operation implement 5 is invalidated, and constant-position control for maintaining the lift arm 17 in a position at the powering-on or at the start of the engine or at a prescribed position is performed.;COPYRIGHT: (C)2014,JPO&INPIT