PURPOSE: To stop a bucket of a work machine more securely even when a solenoid valve for stop of a hydraulic system does not operate normally.
CONSTITUTION: When a bucket 15 invades a stop indication position 42 set around an operator cab of a hydraulic shovel, an obstacle such as trash in hydraulic oil is caught in a spool of a solenoid valve for stop and the movement of the hydraulic shovel becomes dull even if a stop signal is output to the solenoid valve for stop from a controller. Therefore, an engine stop indication position 43 is set more on the operator cab side than the stop indication position 42 and the work is continued while abnormality condition is left as it is, and when the bucket 15 invades this position 43, an engine stop signal is output to a stop solenoid 17 for stopping an engine from the controller to stop the engine itself in emergency. Consequently, a pump which is a hydraulic oil source of each hydraulic actuator 22, 23, 24 stops simultaneously when the engine 16 stops and hydraulic oil does not flow into each hydraulic actuator 22, 23, 24 and stops so that interference between the bucket and operator cab is prevented securely.
NASU KATSUYOSHI
NISHIMURA KOJI
YAMADA OSAMICHI
MATSUDA TAKASHI
ISHIZAKA TOSHIYUKI
NACHI FUJIKOSHI CORP