Complete strategy for daily maintenance of hydraulic system of injection molding machine: the way to ensure stable operation

In the complex mechanical system of injection molding machines, the hydraulic system is undoubtedly the core key, which controls a series of key actions such as mold opening and closing, screw drive, etc.However, the system is extremely prone to difficult problems such as excessive oil temperature and oil leakage. In order to ensure its smooth and efficient operation, the key links of hydraulic oil selection, replacement cycle and cooling system maintenance must be accurately controlled in daily maintenance.
1. Hydraulic oil selection: adaptation is the primary principle
The hydraulic system of an injection molding machine has high requirements for hydraulic oil, and not all oils are capable of it.The first thing to consider is the viscosity characteristics of the hydraulic oil, which needs to be perfectly adapted to the operating temperature and pressure range of the injection molding machine.For common small and medium-sized injection molding machines, under normal operating conditions, hydraulic oils with ISO VG 32 to VG 46 viscosity grades are more suitable. This type of hydraulic oil can maintain good fluidity during the low temperature stage of equipment start-up to ensure the rapid response of each hydraulic component; and when running at high temperature and high pressure, it has sufficient oil film strength to prevent component wear.Moreover, the anti-wear properties of hydraulic oils cannot be ignored. High-quality anti-wear hydraulic oils contain special additives, which can effectively reduce surface wear and extend component life when hydraulic pumps, valves and other components are running at high speed and rubbing frequently.For example, hydraulic oils containing zinc-based anti-wear agents can provide excellent protection for metal contact surfaces under high pressure.In addition, oxidation resistance is also a key indicator. The injection molding machine runs continuously for a long time, and the hydraulic oil is susceptible to oxidation and deterioration due to factors such as high temperature and air. Choosing a hydraulic oil with strong oxidation resistance can greatly reduce sludge and gum generation, ensure system cleanliness and maintain stable performance.
2. Replacement cycle: precise control of aging
The hydraulic oil replacement cycle is directly related to the health of the hydraulic system.Generally speaking, if the injection molding machine is in a high-intensity, long-term continuous operation state, the hydraulic oil needs to be replaced every 3-6 months; if the operation intensity is relatively moderate and the frequency of use is low, the replacement cycle can be extended to 1-2 years.But this is not absolute, and daily monitoring is essential.Through regular extraction of oil samples and observation of changes in color, transparency and odor, the state of hydraulic oil can be preliminarily judged.Normal hydraulic oil should be clear, transparent, slightly yellowish, and have no pungent odor.Once the oil is found to turn black, turbid, or have a pungent burnt smell, it needs to be replaced immediately even if the established replacement cycle is not reached.In addition, detecting changes in the acid value and viscosity of the oil, if the acid value exceeds the standard range or the viscosity deviation is too large, it also indicates that the hydraulic oil can no longer meet the system requirements, and timely replacement can avoid potential failures.
3. Cooling system maintenance: temperature control and stability
The cooling system can be called the “temperature control guard” of the hydraulic system, and its maintenance is directly related to whether the oil temperature can be stabilized within a reasonable range.First of all, the cooling water tank needs to be cleaned regularly. The growth of impurities and microorganisms in the water can easily cause blockage of the cooling pipeline and affect the heat dissipation efficiency.It is recommended to check the water tank at least once a month to remove sediments, and replace the cooling water if necessary to ensure clean water quality.Moreover, the maintenance of cooling fans and radiators cannot be ignored.The fan blades should be checked regularly for damage and deformation to ensure smooth operation and strong wind; the surface of the radiator should be cleaned of dust and debris from time to time to ensure smooth heat exchange and prevent the oil temperature from soaring due to blocked heat dissipation.For injection molding machines with water-cooled cooling systems, it is also necessary to pay attention to the sealing of the cooling water pipeline to avoid water leakage and infiltration into the hydraulic oil, causing the oil to emulsify and deteriorate, weakening the lubrication and heat dissipation properties.In addition, the temperature control valve of the cooling system needs to be calibrated regularly to ensure that it can accurately regulate the amount of cooling water according to the oil temperature, so that the hydraulic oil temperature is always maintained in the ideal range of 40℃-60℃, to create a stable operating environment for the hydraulic system.
The daily maintenance of the hydraulic system of the injection molding machine is a delicate and critical task. Only by strictly following the hydraulic oil selection rules, accurately adjusting the replacement cycle, and carefully maintaining the cooling system can we effectively prevent problems such as excessive oil temperature and oil leakage, so that the hydraulic system can always maintain its peak state, drive the injection molding machine to produce efficiently and stably, and create sustainable value for the enterprise.