Injection molding machine hydraulic fault diagnosis and exclusion
hydraulic system of injection molding machine is the core component of its operation, but due to the many factors, such as improper operation, quality, aging of component parts and even the production environment, fault or failure can be easily generated, which is likely to affect the whole production process. Therefore, it is necessary for operators of injection molding machine to master the principles of hydraulic system and how to maintenance, troubleshooting and fault diagnosis.
Hydraulic system of the injection molding machine is mainly composed of pump, hydraulic control valve, oil cylinder, manifold, pressure control valve, solenoid valve, pressure transmitter, pressure switch and other components. The core component is the hydraulic pump, which is the heart of the system. It provides the source of clean hydraulic pressure and oil. Its reliability is an important factor in the normal operation of injection molding machine and the service life of other major components.
In the diagnosis of injection moulding machine hydraulic system failure, we should first understand the specific situation of machine equipment failure, listen to the descriptions of workers and observe the actual situation, pay close attention to and analyze the fault phenomena. According to the observed fault phenomenon, combined with the principle of hydraulic system, the fault can be preliminarily determined. After the fault is preliminarily determined, the fault diagnosis and exclusion steps should be taken:
1. Check and adjust the pressure gauge. The accuracy of the pressure gauge is the key point of whether the execution of the program is accurate. If an inaccurate pressure gauge is detected, the accuracy of the pressure reading value should be checked and adjusted to the specified value.
2. Check the static and dynamic properties of hydraulic oil. Through the observation of hydraulic oil color and bubble detector, combined with hydraulic oil parameter manual and the industrial or special hydraulic oil the injection moulding machine selects, the thermal stability, oxidation stability and viscosity of hydraulic oil can be determined so as to confirm whether the quality of hydraulic oil has met the specified requirements of injection molding machine.
3. Check the condition of hydraulic system components. Detect, test and inspect various components of the hydraulic system, such as bushings, gaskets, seals, air filters and piping, to ensure that all components of the hydraulic system work normally and meet the requirements.
4. Check the voltage and current of each actuator and solenoid valve. The normal operation of the actuator and solenoid valve depends on whether the power supply and current meet the requirements, and too high or too low voltage will lead to fault. Therefore, the voltage and current of each actuator and solenoid valve of the injection molding machine should be checked to confirm whether they are within the specified range.
5. Identify the cause of the malfunction. After the fault source is preliminarily judged, more detailed diagnosis and exclusion should be performed to determine the cause of the fault. For example, it is necessary to find out whether the valve coil is damp, whether the cleaning air can enter the cavity, and so on.
Finally, after the fault diagnosis and exclusion, check the running state of the injection molding machine again and make sure that the correctly operation is conducting normally.
