What are the common gantry crane hydraulic system failure (three)

What are the common   overhead gantry crane   hydraulic system failure (three)

  Finally malfunctioning. By the operation of the hydraulic system control shows that when an operation fails, the reason for the failure appears on the pilot control the majority of oil and electromagnetic control part, the probability of failure of the main oil line work is minimal. A company of a Taiwan KH700-2 crawler crane outrigger cylinder occurred fault can not be extended. Check the control circuit switches the first leg of the solenoid valve, found that the solenoid valve does not (to determine whether the operation of the solenoid valve, can rely on hearing, touch and other methods to confirm that the solenoid valve operation, and can hear a "click" sound; touch the body, especially when the spool end, can feel the obvious shock).

   But using a multimeter to check the solenoid valve coil freewheeling diode is intact, the line are all normal, you can confirm the fault occurs inside the solenoid. overhead bridge crane  Internal solenoid valve malfunction may have the following two reasons: First, the work coil damage (short circuit or open circuit, burning), and second spool is catching. Good wheeling diode in the coil case, the probability of damage to the coil should be small; further tested with a multimeter the coil, the coil resistance displayed in the normal range, the coil is intact. The valve spools are impurities found stuck disintegration, can slide in the valve body. First with gasoline on the body and spool repeated cleaning, make sure to clean later, and then the hydraulic oil clean again, and then re-assembled and installed to the original position, start the mechanical test machine, everything is back to normal.