1) The fuel tank volume is too small, the heat dissipation area is not enough, and the cooling device has a small capacity.
2) The dosing pump oil supply system that selects the pump capacity according to the fast-forward speed, during operation, most of the excess flow will overflow from the overflow valve under high pressure and generate heat.
3) The unloading circuit in the system is faulty or the unloading circuit is not set. When the pump stops working, the pump cannot be unloaded. The entire flow of the pump overflows under high pressure, causing overflow loss and heating, resulting in temperature rise.
4) The system piping is too long and too long, too much bending, partial pressure loss and large pressure loss along the path.
5) The component accuracy is insufficient and the assembly quality is poor, and the mechanical friction loss between the relative movements is large.
6) The matching clearance of the fittings is too small, or the gap is too large after the wear is used, and the leakage amount is large inside and outside, resulting in volume loss, such as the volumetric efficiency of the pump is lowered, and the temperature rise is fast.
7) The hydraulic system working pressure is adjusted much higher than the actual needs. Sometimes it is necessary to increase the pressure to work because the seal is too tight, or because the seal is damaged or the leak is increased.
8) The climate and operating environment temperature are high, causing the oil temperature to rise.
9) Select the viscosity of the oil is not good, the viscosity is large, the viscous resistance is large, and the viscosity is too small, the leakage increases, and both cases can cause the heat rise.
The danger of excessive temperature rise of injection molding machine oil
1) The machine is thermally deformed, and the moving parts with different thermal expansion coefficients in the hydraulic components are stuck due to the small matching gap, causing malfunction and affecting the transmission precision of the hydraulic system, resulting in deterioration of the working quality of the components.
2) The viscosity of the oil is lowered, the leakage is increased, the volumetric efficiency of the pump and the efficiency of the entire system are significantly reduced. As the viscosity of the oil is lowered, the oil film of the moving parts such as the slide valve is thinned and cut, and the frictional resistance is increased, resulting in an increase in wear.
3) Deform the rubber seal, accelerate the aging failure, reduce the sealing performance and service life, and cause leakage.
4) Accelerate the oxidation and deterioration of the oil, and precipitate the asphalt material to reduce the service life of the hydraulic oil. The precipitate blockages the damper orifice and the slit valve port, resulting in the pressure valve card ※ not working, the metal pipe is elongated, curved, or even broken.
5) The air separation pressure of the oil is lowered, the dissolved air in the oil escapes, and air pockets are generated, resulting in a decrease in the working performance of the hydraulic system.
Injection molding machine oil temperature rise too high treatment method
1) According to different load requirements, always check and adjust the pressure of the relief valve to make it just right.
2) Reasonably select the hydraulic oil, especially the viscosity of the oil. When conditions permit, try to use a lower viscosity to reduce the viscosity friction loss.
3) Improve the lubrication condition of moving parts to reduce friction loss, which is beneficial to reduce working load and reduce heat generation.
4) Improve the assembly quality and accuracy of the hydraulic components and hydraulic system, strictly control the matching clearance of the fittings and improve the lubrication conditions. The sealing material with small friction coefficient and the improved sealing structure are used to reduce the starting force of the hydraulic cylinder as much as possible to reduce the heat generated by the mechanical friction loss.
5) Add a cooling device if necessary.