PROBLEM TO BE SOLVED: To improve switching accuracy and workability of a shift area, by executing operation of a PTO shift mechanism from a combination of position data of a lever and a kind of data of a PTO shaft in use.SOLUTION: A PTO switch for manually operating rotation and stopping of a PTO shaft, a PTO shift operation lever for operating a PTO shift mechanism of a transmission and a hydraulic clutch for intermitting PTO power of the transmission, are respectively provided, the PTO switch, a lever position detection switch for detecting a position of the PTO shift operation lever and a shaft discrimination switch are connected to an input side of a PTO control part, a proportional solenoid valve for engaging-disengaging the hydraulic clutch is also connected to the output side of the PTO control part, respectively, and intermittence of PTO power is controlled by engaging-disengaging the hydraulic clutch by operating the proportional solenoid valve of the output side hydraulic clutch by a combination of an input side signal.SELECTED DRAWING: Figure 8
