Application of VFD (Variable-frequency Drive) in the energy-saving renovation of injection molding machines

Injection molding machines widely used in the plastic production industry, if the Sunwoele VFD (Variable-frequency Drive) is used to control the oil pump, it can not only improve the reliability and service life of the equipment, but also save a lot of power consumption, which greatly improves the economic benefits and benefits of the enterprise. Market Competitiveness.

Power saving principle

The traditional oil pump has been running at high speed for a long time from the beginning of the start-up, but the widely used vane and constant flow pumps have high output pressure and the load will be high, while the oil pump is always in the load state, and the excess flow and pressure overflow through the relief valve to make this part Electric energy is wasted in vain. If the frequency conversion speed control device installed by our company is used to control the oil pump motor, it can control the speed of the oil pump and start and stop in a closed loop. Shock and vibration can greatly improve the service life of the equipment, and save the excess power consumption at no-load and low pressure of the oil pump. The general power saving rate is above 30%, which brings considerable economic benefits to the enterprise and greatly improves the product efficiency Market Competitiveness.

Energy saving scheme

The hydraulic system of an injection molding machine is a system with large pressure and flow fluctuations. During different working stages such as mold opening, mold closing, injection, material return, and ejection, its pressure and flow must change regularly. Most of the time, the actual oil consumption of the load is less than the oil supply of the oil pump, causing the hydraulic oil under high pressure to overflow through hydraulic components such as overflow valves and proportional valves. The overflow part not only does not have any useful work, but also generates heat, which causes the hydraulic oil to heat up, which is energy-consuming and harmful.

Therefore, according to the current working status of the injection molding machine, such as mold opening, mold closing, injection, material return, ejection, etc. The actual oil supply and the actual load flow of the injection molding machine are consistent at any working stage, so that the overflow part of the hydraulic oil is gone, the overflow phenomenon is completely eliminated, the output of the oil pump is reduced, and the electric energy consumption of the oil pump motor is saved.

The frequency conversion energy-saving controller uses the principle of controlling the oil supply motor at different stages to provide the corresponding rotation speed and transmission speed, so that the quantitative pump becomes an energy-saving variable, so as to achieve the best energy-saving state of the injection molding machine.

Advantages of the retrofitted equipment

Obvious energy-saving effect: up to 30%-65%

Optimizing electrical facilities: reducing the VFD (Variable-frequency Drive) load, and reducing the capacity expansion fee for new factories and new factories.

Prolonging the life of the whole machine: the power saver controls the speed standard to be stable, soft start (shock when the power grid is turned on), reduces the vibration of the mold opening and locking, avoids equipment impact, reduces the oil temperature, and prolongs the mission cycle of the seal, so that the life of the whole machine can be extended.

Easy to operate: No need to adjust the power saver during production, the whole process is automatically tracked and controlled, and has multiple protection functions, which is simple, safe and convenient.

Noise reduction: After the transformation, the noise of the equipment is reduced by about 10DB, the operation of the equipment is more stable, and the working environment is improved.

Flexible conversion: The frequency conversion conversion cabinet is convenient for users to switch from power frequency to frequency conversion or from frequency conversion to power frequency at any time.