When the injection molding machine fails, in order to ensure the quick and effective solution of the failure analysis and elimination, certain procedures must be followed, which are roughly as follows.
The First Step Is To Carry Out Symptom Analysis While Maintaining The Scene
A）. Ask the operator
B）. Observe the condition of the whole machine and various operating parameters
C）.Check the monitoring and indicating device
D）.Inching injection molding machine inspection (under permitted conditions)
The second step is to check the injection molding machine (including parts, components and circuits)
A）.Utilize sensory inspection (continuing the process of in-depth observation)
B）.Evaluate the inspection results
The third step is to determine the location of the fault
A）.Identify the system structure and determine the test method
B）.System detection
Common fault handling of injection molding machine
After a rough analysis, it is necessary to prescribe the right medicine, so how to deal with common faults, please see next!
1. Oil pump motor and oil pump start, but no pressure.
A）.The wiring of the proportional valve is loose or the coil is burned --> check whether the proportional pressure valve is connected.
B）.Impurities block the control oil port of the proportional pressure valve --> remove the proportional pressure valve to remove impurities.
C）.The hydraulic oil is unclean, and debris accumulates on the surface of the oil filter, preventing the pressure oil from being clean and causing damage. ——>Clean the oil filter and replace the hydraulic oil.
D）.The internal oil leakage of the oil pump is caused by excessive use, internal loss or dirty pressure oil. ——>Repair or replace the oil pump.
E）.Leakage of oil cylinders, oil pipes and joints --> eliminate leaks.
F）.The spool is stuck --> check whether the spool moves normally.
2. No mode locking
A）.The wiring of the travel switch of the safety door is loose or damaged --> connect the wire or replace the travel switch.
B）.The coil of the mold clamping solenoid valve may move into the valve and move with the spool --> clean or replace the mold clamping and mold opening control valves.
C）.The directional valve may not reset --> clean the directional valve.
D）.The thimble cannot be returned to its original position --> check whether the thimble moves normally.
3. No glue
A）.The coil of the injection solenoid valve may have been burned, or a foreign object has entered the directional valve and stuck the valve core to move. ——>Clean or replace the injection solenoid valve.
B）.The pressure is too low --> increase the injection pressure.
C）.The temperature during injection molding is too low --> adjust the thermometer to increase the temperature to the required point. If the temperature cannot be raised after adjusting the thermometer, check whether the electric heating tube and fuse are burnt or loose. If it is broken, replace it with a new one. .
D）.The wiring of the injection directional valve is loose or in poor contact --> connect the wire head of the directional valve properly.
4. Non-melting glue, melting glue is too slow
A）.The travel switch is out of order or in an improper position --> adjust the travel switch position.
B）.Improper throttle adjustment --> adjust to proper flow.
C）.The coil of the melt glue solenoid valve may have been burned, or foreign matter has entered the directional valve, and the valve core is stuck to move --> clean or replace the melt glue control valve.
D）.Insufficient temperature, causing motor overload --> check whether the heating tube is burnt out (at this time, the melting motor should be strictly stopped, otherwise the screw will be damaged.)
5. The melt glue screw rotates, but the glue does not enter the barrel
A）.The retreat pressure of the melt is too high, the throttle valve is damaged or improperly adjusted --> adjust or replace the one-way throttle valve for injection.
B）.Insufficient water transport leads to high temperature, which hinders the rubber material from entering the screw --> adjust the water transport volume and take out the bonded rubber blocks.
C）.There is no material in the drop hopper --> add material to the hopper.
6. Shooting platform does not move
A）.The travel limit switch of the injection platform is adjusted to be pressed by the bumper --> adjustment.
B）The coil of the ejector moving solenoid valve may have been burned or foreign matter has entered the directional valve and stuck the spool to move --> clean or replace the solenoid valve.
7. Can not adjust the mold
A）.The Corinthian thread was burned to death due to uncleanness or no lubricating oil --> Clean the Corinthian and the adjusting screw, repair the burnt part, and add molybdenum disulfide grease to lubricate.
B）.The coil of the modulus adjustment solenoid valve may have been burned, or a foreign object has entered the square inlet valve and stuck the valve core --> clean or replace the solenoid valve.
8. mold opening sound
A）.The mold opening limit switch is not pressed or fails --> adjust or replace the limit switch.
B）.The fastening screw of the slow solenoid valve is loose, or the spool is stuck --> adjust to an obvious slow speed.
C）.The position of the mold opening stop stroke switch is adjusted too far, so that the piston hits the cylinder cover when the mold opening stops --> adjust the mold opening stop switch to an appropriate position.
D）.The machine hinge, steel sleeve or hinge edge are worn, and the fixing screw in a certain part is loose --> adjust or replace.
9. Pressure oil is too high
A）.The pressure of the oil pump is too high --> it should be adjusted to the demand pressure of the rubber.
B）.The pump is damaged and the pressure oil concentration is too low --> check the oil pump and oil quality.
C）.Insufficient pressure oil --> increase the pressure oil.
D）.There is something wrong with the cooling system and the water is not enough --> repair the cooling system.
10. semi-automatic failure
A）.The semi-automatic cycle of this machine is achieved by moving the stroke of the mechanical action, touching the travel switches and time switches of the electrical appliances, sending electrical signals, and controlling the oil switches. If in the manual state, every action is normal, but the semi-automatic failure is mostly due to the failure of the electrical travel switch and the time switch to send out a signal --> first observe at which stage the semi-automatic action fails, and refer to the "action cycle diagram" "Find out the corresponding control components and check them to solve them.
11. Automatic failure
A）.The electric eye is malfunctioning, the fixing screw is loose or the light is not focused --> restore the electric eye to its function.
B）.The time switch is malfunctioning or damaged --> adjust or change the name of the time switch.
C）.The heating tube is damaged --> replace it.
D）.Bad thermocouple wiring --> tight.
E）.Bad thermocouple --> replace.
Related Reading：
Plastic Injection Mold Base Functions and Structure
