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Causes Of Failure Of Hydraulic Part Of High-speed Precision Injection Molding Machine

Dec 06, 2019

(ONE): Hydraulic oil pollution:

(1): Air is mixed with oil. Mainly due to poor fitting of pipe joints, hydraulic pumps and hydraulic cylinders. There are air bubbles in the fuel tank.

(2): Water is mixed in the oil. Makes the oil milky white. The main reason is that the cooler leaks water or the environment is humid.

(3): Solid impurities are mixed in the oil. Mainly chips, welding slag, rust and metal powder.

(4): A colloidal substance is produced in the oil. The main banquet is that the seal is eroded by the oil or the oil is deteriorated, so that a gelatinous substance is produced in the oil. This gelatinous substance often causes the small holes to be blocked.

(TWO): What effect does temperature have on the viscosity of hydraulic oil:

Effects: 1): When the temperature increases, the viscosity of the oil decreases. Changes in oil viscosity directly affect the performance and leakage of hydraulic systems. (Normal temperature is between 30 ~ 50 ℃)

(Three): crawling failure:


(1): Poor lubrication conditions. "Pause-Slide-Pause" appears. Increase the amount of lubrication.

(2): Immerse the air in the hydraulic system. Need to vent.

(3): Reasons for mechanical rigidity. Parts wear and deform, causing changes in friction and creep. Replace parts.

(Four): After starting for a period of time, the oil pump sounds.


(1): The quality of the suction pipe is not good or the throat code is not tightened. Remove the filter and check for deformation. Whether the suction pipe is stratified. Replace the tubing and strainer.

(2): The filter is not clean. Excessive impurities in hydraulic oil. Clean the filter.

(3): Oil pump wear: Check the oil pump oil pan and rotor end face for wear. Replace the oil pump.

(Five): After the motor starts, the pressure gauge has pressure and no flow.


(1): DA board is broken, repair DA board.

(2): The overflow valve is stuck. Remove the relief valve for inspection, clean the relief valve or replace the pressure gauge for inspection.

(Six): No pressure flow

(1): Check whether the rotation direction of the motor oil pump is normal.

(2): Check for oil leakage.

(3): Check the pressure flow valve for current.

(4): Check whether the inner hexagon socket is pressed against the pressure valve core, and replace or clean it.