DECK ELEVATION CONTROL DEVICE FOR DUMP TRUCK

摘要

PROBLEM TO BE SOLVED: To stabilize attitude of a deck and a car body while effectively reducing the shock to be generated in starting to rock the deck downward, and to shorten the time to be required for selecting a valve in a deck elevation control device for dump truck for controlling the elevation of the deck while using a spool type dump selector valve. SOLUTION: When a lowering operating part 42 is operated in the condition that a spool valve element 18 is positioned at a deck hoisting position U or a neutral position N, a spool driving means 30 is controlled so that the flow change rate of the oil passing through a selector valve 8 in a slide block from the neutral position N to the deck lowering position D of the spool valve element 18 is maintained nearly constant.