OPERATION CONTROL DEVICE FOR WORKING MACHINE OF CONSTRUCTION VEHICLE

PURPOSE:To simplify the titled device, to reduce the cost of the device and to improve operability at the time of manual operation and control accuracy at the time of automatic control by forming a direction control valve in a main hydraulic circuit and using the valve for both manual and automatic control. CONSTITUTION:At the time of manual operation, an operation signal + or -Vs for a boom 1 is outputted from a computing element 9 on the basis of an operation signal (s) corresponding to the operation of an operation lever 7 and a characteristic storing value from a storage device 10 for manual operation. At the time of automatic control, a control signal + or -Ve is outputted from a computing element 14 on the basis of a deviation signal etheta between a current position signal theta of the boom 1 and its objective position signal theta0 and a characteristic storing value from storage device 5 for automatic control. Both the signals are sent to a controller 18 through a change-over switch 17. The controller 18 decides up or down of the boom 1 and sends any one of the signals + or -Vs and + or -Ve to a direction control valve 3. Consequently, the up/down control of the boom 1 is executed.