DEVICE FOR CONTROLLING THE ROTATION SPEED OF AN ENGINE FOR A HYDRAULIC WORKING MACHINE

摘要

A control device for properly controlling the switching of the rotation speed of an engine from a designated engine rotation speed to an energy-saving lower engine rotation speed when the operation of a hydraulic working machine is at halt without any particular switching operation by an operator, wherein when all the operating levers (14 to 21) are shifted to a neutral position to halt the operation, in a case where the operating speed of the operating lever operated last is a lower operating speed, a delay time is set to be longer than when the operating speed is higher, wherein when the operating levers (14 to 21) are held at the neutral position until this delay time is over, the engine rotation speed is switched to the lower engine speed, and wherein when any of the operating levers is operated before the delay time is over, the engine rotation speed is controlled to be kept at the designated rotation speed.