HYDRAULIC CIRCUIT FOR CONSTRUCTION MACHINE

摘要

[PROBLEMS] To prevent negative effect such as worsening in operability while achieving a cushioning function in quick operation. [MEANS FOR SOLVING PROBLEMS] In a hydraulic circuit for a construction machine, a primary pressure is supplied from a pilot pump (30) to pressure reducing valves (27, 28) of a remote control valve (26) for operating a hydraulic pilot-type control valve (23), and a first restriction (32) for reducing the primary pressure is provided on the primary side of the pressure reducing valves (27, 28). Bleed off lines (33, 34) for communicating pilot lines (24, 25) to a tank (T) are provided in the circuit, and second restrictions (35, 36) are arranged in the bleed off lines (34, 35). The second restrictions (35, 36) cause pilot pressures, supplied to pilot ports (23a, 23b) of the control valve (23), to rise more gradually.