A HYDRAULIC SYSTEM FOR CONTROLLING A DAMPING DEVICE AND A SHOCK ABSORBER DEVICE OF WHEEL TYPE EXCAVATOR

摘要

PURPOSE: Brake device of a wheel typed excavator and a hydraulic system for controlling a suspension are provided to prevent a parking brake device from being damaged, to simplify structure by simplifying a circuit and to improve operation reliability. CONSTITUTION: Hydraulic system comprises two hydraulic pumps(2a,2b) driven by an engine(1); a travelling brake cylinder(7) actuated by one of the hydraulic pumps; a parking brake cylinder(13) and a suspension locking cylinder(16) actuated by the other of the hydraulic pump; a travelling brake valve(5) mounted between the hydraulic pump and the travelling brake cylinder; a first channel converting solenoid valve(10) installed between the hydraulic pump and the parking brake cylinder; a second channel converting solenoid valve controlling the suspension locking cylinder; and a third channel converting solenoid valve(20) mounted between the travelling brake valve and a brake cutoff valve(3) to control actuation of spool in the travelling brake valve.