(1) Shock occurs when the flow of the excavator is reversed
The spool control side of the directional valve can be cut into a cone angle of 1.5 ° ~ 4 ° (the original value length depends on the length of the sealing side) or an axial three-angle buffer groove.
(2) Throttle buffer device fails to produce impact
① The steel ball and valve seat in the hydraulic cylinder buffer device have poor sealing oil, the paper pad at the end cover is damaged, the lock nut of the piston is loose, and the clearance between the piston and the cylinder hole is too large.
Replace the steel ball, grind the joint of the valve seat, replace with a new paper pad, tighten the lock nut or remake the piston (the clearance for cooperation with the cylinder bore is 0.03mm).
②The buffer plunger at the buffer piston end is provided with a triangular groove. When the oil returns to the oil through the triangular groove, it is buffered. When the outer edge of the buffer plunger and the inner hole of the end cover are worn and the fit gap is too large, the triangular groove will not buffer. The piston and buffer plunger can be remade according to the size of the inner hole of the end cap, or after the buffer plunger is rounded, a layer of hard inscription is plated on the surface, and then the clearance is matched according to the size of the inner hole of the end cap.
③ There is a throttle valve outside the end of the buffer cylinder. The throttle nut in the throttle valve is loose or improperly adjusted, resulting in hydraulic shock. The nut can be tightened or readjusted.
④There is a one-way throttle valve (damper) at both ends of the hydraulic directional valve. If the throttle valve is improperly adjusted or the one-way valve is poorly sealed, it will cause the working device to impact when it changes direction. At this time, tighten the throttle adjusting screw appropriately to increase the buffer damping. If there is still an impact, it can be judged that there is a problem with the check valve seal, and then check the check valve and its seat sealing problem.
(3) There is air in the hydraulic system
There is a lot of air in the hydraulic system. The air in the reversing valve is sometimes compressed and sometimes released, causing hydraulic shock. Check the air inlet, take preventive measures, and remove the air from the system.
