Application of the hottest inverter in injection m

Application of frequency converter in injection molding machine

I. advantages of using frequency converter in injection molding machine

1. Energy saving

three groups of asynchronous AC motors commonly used in injection molding machine cannot change speed, and the flow of output hydraulic oil of the quantitative vane pump it drives cannot be changed. When the injection molding machine operates at a low speed, the excess flow flows back to the oil tank through the overflow valve, causing a large loss of energy. The frequency converter can adjust the speed of the motor according to the command of the control system, so that the flow of hydraulic oil output by the vane pump can be changed according to the action speed of the injection molding machine, reducing the energy consumption of hydraulic oil flowing back to the oil tank from the overflow valve, thus saving a lot of electric energy. According to the different injection products, the power consumption of the motor is monitored in real time, and the power saving rate is 20 ~ 70%

2. Avoid personal safety accidents

after the injection molding machine is equipped with a frequency converter, because the operator does not output the speed analog quantity of the computer of the injection molding machine when taking parts, cleaning and repairing the mold, the motor is in a stopped state, and the hydraulic system has no pressure, which avoids the misoperation of the machinery and completely eliminates the occurrence of personal safety accidents of the injection molding machine

3. Soft start

under power frequency conditions, the motor adopts star delta step-down delayed start. At this time, the current is 4 ~ 7 times the rated current of the motor. If multiple high-power motors are started at the same time, it will have a great impact on the electricity. After adopting frequency conversion speed regulation, the motor can be soft started only under the rated current, and the current is smooth without impact, which reduces the impact of starting current on the motor and electricity. It is reported that please re tension the tensioning wheel;, The service life of the motor is prolonged

4. Reduce reactive power

reactive power not only increases line loss and equipment heating, but also reduces the electric active power due to the reduction of power factors. After using the frequency conversion speed regulation energy-saving control device, due to the function of the filter capacitor in the frequency converter, the power factor is close to 1, which increases the active power of electricity, thus saving the energy consumed by reactive power

II. Problems and solutions of frequency converter in the energy-saving application of injection molding machine

1. After the injection molding machine is equipped with frequency conversion and speed regulation, the speed of the main motor changes with the speed of each action of the injection molding machine. The injection molding production cycle time is short, and the frequent rotation speed of the action causes the main motor to be in the process of acceleration and deceleration frequently. Due to the long acceleration and deceleration response time of the motor, the injection molding cycle time increases, A reduction in productivity. The frequency converter produced by our company can be controlled online with the computer of the injection molding machine. Through the control of the frequency converter by the computer, the decoupling adjustment of the output frequency and output torque of the frequency converter can be realized, so as to achieve the best cooperation between the frequency converter and the various actions of the injection molding process, and solve the bottleneck of the production efficiency reduction caused by the application of frequency conversion and energy saving technology in the injection molding machine

2. With the decrease of the motor speed, the speed of the fan blade connected to the motor rotor also decreases, heat-resistant gloves; Goggles; Copper scraper; Copper brush; Copper wire; Stearic acid; Electric drill; Cylinder ruler; Cotton cloth causes poor heat dissipation of the motor. In addition, the insulation effect of the insulation layer is reduced under the impact of the frequency conversion voltage of the frequency converter. At present, motor manufacturers have specially produced variable-frequency motors that bring environmental benefits, that is, improvements have been made to these two points. The motor fan is independent of the rotor, the speed is not affected by the reduction of motor speed, and the insulation layer also adopts better materials, thus solving the problem that the frequency converter affects the service life of the motor

3. When the vane pump works, it mainly depends on the rotor running at high speed to throw out the blades, so as to achieve the purpose of oil absorption. If the rotor speed decreases, the blades will not have enough centrifugal force to effectively compress the stator surface, so the internal leakage of the pump will increase and the efficiency will be significantly reduced. When the speed is lower than a certain critical value (such as 400r/min), the oil absorption capacity of the vane pump will become poor, or even unable to produce oil. When this problem occurs, the frequency setting signal gain must be increased. In addition, the development of internal gear pump will gradually replace vane pump as the mainstream of the development of injection molding oil pump, so as to solve the problem of poor low-speed oil absorption of vane pump

4. During high-voltage mold locking and slow mold opening, the frequency converter operates in the state of low-speed and high torque, and the current is easy to exceed the rated value, resulting in overcurrent protection. The input end of the frequency converter produced by our company is equipped with the input point of mold locking and mold opening, which is connected with the output point of mold locking and mold opening of the injection molding machine computer. Through the specific frequency converter software, the motor maintains high-speed operation during mold opening and mold locking, so as to avoid the state of low-speed and high torque