CONTROLLER OF HYDRAULIC PUMP FOR WORK MACHINE OF WORKING VEHICLE

PROBLEM TO BE SOLVED: To provide a capacity controller of a hydraulic pump for a working vehicle capable of surely detecting an excavating operation and reducing power loss. SOLUTION: A bottom pressure detector 45 of a cylinder, an operating position detecting means 31, and the capacity controller 41 of the variable capacity type hydraulic pump 26 are connected with a controller 50 formed by a sequence circuit. The controller 50 inputs a detecting signal from the bottom pressure detector 45, and determines that an excavating operation starts when bottom pressure of a cylinder continues in a state with a designate value or less for a designated time and then, when the bottom pressure of the cylinder exceeds the designate value. Consequently, capacity of the variable capacity type hydraulic pump 26 is controlled so as to reduce to a designated capacity which is the maximum capacity or less. The controller 50 determines with a signal from the operating position detecting means 31 that the excavating operation is finished when a transmission of the working vehicle is set at a neutral gear or a backward gear, and voluminal control of the hydraulic pump is stopped. COPYRIGHT: (C)2004,JPO&NCIPI