| 摘要 |
PROBLEM TO BE SOLVED: To allow a combine harvester to travel without troubles even in the event of a failure of a flow dividing valve by providing a hydraulic circuit structure such that pressure oil discharged from one hydraulic pump is supplied to a traveling hydraulic transmission and a mowing hydraulic transmission by the flow dividing valve. SOLUTION: The hydraulic circuit includes: a main hydraulic pump (11) which delivers pressure oil to a traveling clutch operation hydraulic circuit (T) and a main hydraulic circuit (W) which performs machine body attitude control and mowing/auger lifting control; and a sub-hydraulic pump (22) which delivers pressure oil to a traveling continuously variable transmission circuit (1) and a mowing continuously variable transmission circuit (2). The pressure oil by the sub-hydraulic pump (22) is distributed to the traveling continuously variable transmission circuit (1) and the mowing continuously variable transmission circuit (2) by a variable-speed flow dividing valve (23), and a variable-speed supply conduit (41) for delivering pressure oil from the sub-hydraulic pump (22) to the variable-speed flow dividing valve (23) and a traveling distribution conduit (43) for delivering the pressure oil from the variable-speed flow dividing valve (23) to the traveling continuously variable transmission circuit (1) are allowed to communicate with each other by an emergency path (46) through an emergency check valve (40) which performs releasing operation at a predetermined pressure. COPYRIGHT: (C)2011,JPO&INPIT |
