avoid the rise of oil temperature in injection
avoid the rise of oil temperature in injection
In the injection molding industry, the rise of oil temperature annoys us. The rise of oil temperature will not only affect the work of the machine, but also seriously affect the service life of the machine. How can we prevent the temperature rise of injection molding oil? We should analyze from the aspects of viscosity index, whether there is a good hydraulic heat dissipation system, viscosity and other comprehensive properties.
1. Viscosity index (VI)
This index directly reflects the nature of oil viscosity changing with temperature (i.e. viscosity temperature characteristics of oil). The high viscosity index of oil indicates that the viscosity of oil changes less with temperature; On the contrary, it is larger.
The viscosity index of anti-wear hydraulic oil from well-known foreign manufacturers is VI ≥ 110, and the viscosity index of domestic advanced anti-wear hydraulic oil is about VI = 95. The viscosity index of high viscosity index hydraulic oil (HV) and multi-stage engine oil produced abroad is VI > 140; Domestic can not reach this level.
The decrease of viscosity index will reduce the ambient temperature range to which the oil is suitable. If it is not necessary to use, consult the oil manufacturer for relevant data, adjust the oil use range appropriately, and change the relevant set values of the equipment (such as limit temperature, etc.) if necessary.
2. Good hydraulic oil cooling system
For the improvement of the hydraulic oil heat dissipation system (more specifically, the hydraulic oil temperature control system) of the injection molding machine, although the specific methods adopted by various manufacturers are different, the basic idea is the same. Whether the hydraulic oil radiator is blocked by dirt, resulting in the decline of heat dissipation efficiency, and clean the radiator when necessary.
3. Hydraulic oil viscosity
(ISO VG, viscosity unit: mm2 / s) the principle for determining the viscosity of hydraulic oil is to make the viscosity of hydraulic oil (for components such as pumps and motors) in the best range (16-36x10-6mm2 / s) on the premise of considering the working temperature and efficiency of hydraulic circuit;
Viscosity of short-time cold start corresponding to the lowest ambient temperature ≤ 1000x10-6mm2 / S; And the viscosity corresponding to the maximum allowable leakage oil temperature of 90 ℃ in a short time ≥ 10x10-6mm2 / s.
4. Other comprehensive performance
Because the hydraulic system of modern injection molding machine has high working pressure (≥ 14MPa) and the maximum allowable working oil temperature of hydraulic oil is also high (about 50 ℃), in order to ensure that the hydraulic system can work normally in the normal oil change cycle, the lubricating property, oxidation stability, wear resistance, rust and corrosion resistance, emulsification resistance, foam resistance It has good quality in shear stability and extreme pressure load.
In particular, when selecting alternative oil, be sure to meet the requirements of the standard of the alternative oil. Otherwise, serious problems such as system overheating and component damage may occur due to unsatisfactory oil quality during the use of the equipment.
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