TRAVEL OPERATION CIRCUIT OF OPERATING MACHINE

摘要

PROBLEM TO BE SOLVED: To provide a travel operation circuit of an operating machine that can be driven in a state in which start shock is hard to generate in spite of having a counterbalance valve. SOLUTION: A sliding spool of the counterbalance valve 20 is provided with a buffering oil pathway 25 with a reduced portion 24. When the counterbalance valve 20 shifts to an opening position O, the buffering oil pathway 25 links a feeding side oil pathway 28 with an exhaust side oil pathway 29, making a part of pressure oil fed from a control valve 12 to the feeding side oil pathway 28 outflow to the exhaust side oil pathway 29.