The reasons and solutions are as follows:
(1) The valve core is stuck or the valve hole is blocked. When the flow valve or directional valve spool is stuck or the valve hole is blocked, the hydraulic cylinder is prone to malfunction or malfunction. At this time, check the contamination of the oil; check whether the dirt or colloidal sediment is stuck on the valve core or block the valve hole; check the wear of the valve body, clean and replace the system filter, clean the oil tank, and replace the hydraulic medium.
(2) The piston rod and the cylinder are stuck or the hydraulic cylinder is blocked. At this time, no matter how it is operated, the hydraulic cylinder does not move or moves very little. At this time, it is necessary to check whether the seal of the piston and piston rod is too tight, whether it enters the dirt and colloidal sediment: whether the axis line of the piston rod and the cylinder barrel is aligned, whether the wearing parts and seals are invalid, and whether the load is too high Big.
(3) The control pressure of the hydraulic system is too low. The throttling resistance in the control pipeline may be too large, the flow valve is not properly adjusted, the control pressure is not suitable, and the pressure source is disturbed. At this time, the control pressure source should be checked to ensure that the pressure is adjusted to the specified value of the system.
(4) Air enters into the hydraulic system. Mainly because there are leaks in the system. At this time, check the liquid level of the hydraulic oil tank, the seals and pipe joints on the suction side of the hydraulic pump, and whether the oil suction strainer is too dirty. If so, the hydraulic oil should be replenished, the seals and pipe joints should be treated, and the coarse filter element should be cleaned or replaced.
(5) The initial action of the hydraulic cylinder is slow. When the temperature is low, the viscosity of the hydraulic oil is high and the fluidity is poor, resulting in the slow action of the hydraulic cylinder. The improvement method is to replace the hydraulic oil with better viscosity-temperature performance. At low temperature, the oil temperature at startup can be increased with the help of a heater or by the machine itself. The normal working oil temperature of the system should be maintained at about 40 degree .
