The most common fault causes and troubleshooting o

2022-09-22
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The most common fault causes and troubleshooting of plastic injection molding machine

1 The abnormal rise of oil temperature may be caused by abnormal cooling system or high heat of oil pressure components during operation

⑴ but the system is abnormal

① the cooling water supply is insufficient. The method is to select a rod with one end hard and one end soft. For example, the water switch is not fully opened, the water pressure is insufficient, or the flow of the water pump does not meet the needs

② the pipeline is blocked, such as insufficient heat dissipation capacity of filtration and cooling tower, or damaged or the temperature is too high

③ the cooling water temperature is too high, such as the cooling tower has insufficient heat dissipation capacity, or is damaged or the temperature is too high

⑵ the hydraulic system produces high heat

① the oil pump is damaged, and the internal parts are worn during high-speed rotation to produce high heat

② the pressure is not adjusted properly, and the hydraulic system is overheated under high pressure for a long time

③ the oil pressure element conceives a single pulse in connection with the pulse mixing work port type internal leakage, such as the direction valve buckle is broken or the seal is damaged, so that the high-pressure oil will generate heat when flowing through a small space

2 Noise generation

abnormal noise generation indicates that there are parts damaged or improperly adjusted. Find out the cause according to the location of the noise and repair it immediately

⑴ insufficient hydraulic oil in the oil tank, air suction by the oil pump or dirt blockage of the oil filter will cause oil shortage of the oil pump, causing bubbles in the oil to discharge and impact the blades to produce noise. The solution is to check the oil volume, prevent air suction and clean the oil filter

⑵ hydraulic oil has high viscosity and increases flow resistance, so it needs to be replaced with a more suitable hydraulic oil

⑶ since the bearing or blade of the oil pump or motor is damaged and the concentricity deviation of the coupling causes noise, it is necessary to adjust the concentricity or replace parts

⑷ the reaction of the directional valve fails, but the function is still there. For example, the valve core is worn, the internal leakage burr is blocked, and the movement is not flexible. The failure of the solenoid valve due to insufficient current will also produce noise. The solution is to clean the valve core. If the valve core is worn, it must be replaced with new parts, and the current must be stable and sufficient

(5) the hydraulic components are damaged or the oil pipeline is blocked, which makes the hydraulic oil tell that the flow is noise

⑥ in case of mechanical failure, bearing wear or lack of lubricating oil or loose parts, find out the reason and fasten or replace the parts to ensure that there is enough lubricating oil

3. The production of finished products is unstable or unqualified

in a stable production cycle, the unstable quality of finished products is mostly mechanical parts, and most screws adopt 4140 H. T. caused by steel manufacturing wear or improper adjustment

⑴ wear of screw, check ring and barrel

⑵ the seal ring in the injection cylinder is damaged, resulting in internal leakage

⑶ the temperature control of the heating cylinder is unstable

⑷ the pressure and speed control part is abnormal

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