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

Injection molding machines widely used in the plastic manufacturing industry, if 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, greatly improving the economic benefits and efficiency of the enterprise. Market Competitiveness.

Principle of power saving

The traditional oil pump has been running at high speed for a long time since it was started. However, the vane and constant flow pumps that are widely used at present have a high output pressure and a high load. The oil pump is always under load. The excess flow and pressure overflow through the relief valve, causing this part to overflow. Electricity is wasted. If we use the variable frequency speed control device installed by our company to control the oil pump motor, it can control the oil pump speed and start and stop in a closed loop. The oil pump can achieve soft start, reduce the oil supply of the equipment, achieve precise control, achieve soft start of the motor, and reduce the impact on the equipment. Shock and vibration can greatly extend the service life of the equipment, and save excess power consumption when no-load and low-pressure oil pumps. The general power saving rate is more than 30%, which brings considerable economic benefits to the enterprise and greatly improves the product's Market Competitiveness.

Energy saving plan

The hydraulic system of the injection molding machine is a system with large pressure and flow fluctuations. During different working stages such as mold opening, mold closing, glue injection, material return, and ejection, the pressure and flow rate will 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 relief valves and proportional valves. This overflow part not only does not perform any useful work, but also generates heat, causing the hydraulic oil to heat up, which is both 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 and other stages, as well as the high requirements for pressure and speed, the speed of the oil pump is automatically adjusted, and the oil supply amount of the oil pump is adjusted to make the oil pump The actual oil supply volume is consistent with the actual load flow of the injection molding machine at any working stage. In this way, there is no overflow of hydraulic oil, completely eliminating the overflow phenomenon, reducing the oil pump output, and saving the power consumption of the oil pump motor.

The variable frequency energy-saving controller uses the principle of controlling the oil supply motor at different stages to provide corresponding rotational speeds and corresponding transmission speeds, turning the quantitative pump into an energy-saving variable, to achieve the best energy-saving state of the injection molding machine.

Advantages of modified equipment

The energy saving effect is obvious: up to 30%-65%

Optimize electrical facilities: reduce VFD (Variable-frequency Drive) load and reduce capacity expansion costs for newly opened and newly built factories.

Extend the life of the whole machine: The power saver control speed standard is stable, soft start (power grid shock), reduce the vibration of mold opening and locking, avoid equipment impact, reduce the oil temperature, extend the service life of the seal, thereby extending the life of the whole machine.

Easy to operate: There is no need to adjust the power saver during production, the whole process is automatically tracked and controlled, and it has a variety of protection functions, which is simple, safe and convenient.

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

Flexible conversion: The frequency conversion conversion cabinet facilitates users to switch from power frequency to variable frequency or from variable frequency to power frequency at any time.