Complete strategy for troubleshooting and repairing the failure of the injection molding machine to close the mold in place

In the process of automated production of injection molding machines, once the mold closing is not in place, the entire production process will stop abruptly, seriously affecting production efficiency and product delivery.This failure may originate from multiple complex systems, and it is essential to accurately and quickly identify the root cause of the failure and implement repairs.The following will analyze the causes in depth from the three key levels of mechanical components, electrical systems, and hydraulic systems, and share practical diagnostic techniques and repair methods.
1. Troubleshooting and repair of mechanical components
As the direct executor of the mold closing action of the injection molding machine, the mechanical structure, any minor defects may cause the mold closing to be blocked.First of all, check the guide post and guide sleeve. Long-term reciprocating movement can easily wear them out. If the gap is too large, the mold will deviate from the correct trajectory when the mold is closed, and it will be skewed and unable to be in place.At this time, a measuring tape can be used to measure the gap. If the allowable tolerance of the equipment (generally 0.1-0.3mm) is exceeded, the worn parts need to be replaced in time.Secondly, pay attention to the transmission components such as connecting rods and elbows. Under high-intensity work, the connecting pins may loose or break, resulting in uneven transmission of clamping force.Through visual observation and manual shaking of the connecting rod, abnormalities can be detected, and the pin shaft should be tightened or replaced immediately after the problem is found.Moreover, the problems of the mold itself cannot be ignored, such as wear of the positioning ring and foreign objects stuck on the parting surface, which will hinder the mold from closing.Cleaning the parting surface, repairing or replacing the positioning ring, and ensuring the precise docking of the mold are effective ways to solve such problems.
2. Troubleshooting and repair of electrical systems
The electrical system is like the “nervous system” of an injection molding machine, controlling the coordinated operation of various components.When the mold closing is not in place, first check the sensor failure. If the mold closing position sensor fails, it will send an error signal to the control system, causing the machine to misjudge the mold closing state.With the help of a multimeter, the sensor resistance value or output voltage is detected, and the normal parameters are compared. If the deviation is too large, it needs to be replaced.Secondly, check the relays and contactors of the control circuit. Frequent on-off can easily ablate their contacts, resulting in circuit disconnection or poor contact, which affects the transmission of mold closing instructions.Check the appearance of the contacts. If there are black burn marks, they need to be polished, repaired or replaced.In addition, the aging and damage of electrical circuits, causing short circuits or circuit breaks, will also interfere with the mold closing action.Investigate along the line, repair the damaged areas and ensure that the line is firmly connected to ensure the stable transmission of electrical signals.
3. Troubleshooting and repair of hydraulic system
The hydraulic system provides strong power for mold closing, and its failure often leads to weak or insufficient mold closing.On the one hand, check the hydraulic pump. If the wear in the pump is serious and the output oil pressure is insufficient, the pressure required for mold closing cannot be met.When observing the outlet pressure value of the hydraulic pump, which is lower than the rated compression pressure of the equipment (such as 10-20MPa for common injection molding machines), consider repairing or replacing the pump body.On the other hand, the failure of the hydraulic valve cannot be ignored. The valve core of the reversing valve is stuck, which will cause the flow of oil to be wrong or blocked, and affect the action of the clamping cylinder.Manually operate the directional control valve to feel its flexibility. If it is stuck, disassemble and clean the valve core and replace the seal.In addition, hydraulic oil problems may also be the culprit. Abnormal viscosity of the oil or mixing with impurities will increase flow resistance and reduce system efficiency.Detect the viscosity and cleanliness of the oil, and replace the hydraulic oil if necessary to ensure the smooth operation of the hydraulic system.
In the actual troubleshooting of faults, the segmented diagnosis method can be used to predict the most likely system to go wrong based on experience, and quickly inspect key parts; if no abnormalities are found, other systems can be investigated in turn.At the same time, daily maintenance is essential. Regular cleaning of mechanical parts, inspection of electrical circuits, and replacement of hydraulic oil can effectively reduce the probability of failure when the mold is not in place, ensure the stable and efficient operation of the injection molding machine, and escort the production of the enterprise.