PROBLEM TO BE SOLVED: To enhance efficiency of harvesting work by securing functions of a reel lifting and lowering cylinder and a second mower lifting and lowering cylinder required for the harvesting work even when the amount of an action oil is in short supply caused by the increase of a traveling load. SOLUTION: A hydraulic circuit is constructed by feeding a pressurized oil discharged from a hydraulic pump (51) to a travelling hydraulic circuit (54) for regulating a plurality of hydraulic clutches (57, 58, 59, 60) and a harvesting hydraulic circuit (55) for regulating a harvesting cylinder (61) for lifting and lowering a harvesting unit (4), and diverging the pressurized oil fed through either one of the travelling hydraulic circuit (54) and the harvesting hydraulic circuit (55) by a priority type flow dividing valve (62) to feed a constant flow of the pressurized oil to a hydraulic circuit (64) in the front part of a machine body equipped with the reel lifting and lowering cylinder (14) and the second mower lifting and lowering cylinder (66), while feeding the residual pressurized oil to a machine body hydraulic circuit (56) equipped with rolling cylinders (68, 69) and a pitching cylinder (70). COPYRIGHT: (C)2012,JPO&INPIT
