Characteristics of electrohydraulic hybrid servo energy saving plastic injection molding machine
The injection molding industry is facing a rapid development opportunity. However, in the cost composition of injection molding products, electricity accounts for a considerable proportion. According to the demand of injection molding equipment technology, the power consumption of the traditional injection pump motor accounts for 80% - 90%. With the increasing attention to energy issues, especially the concept of circular economy put forward in recent years in China, energy conservation has become more and more important. The design and manufacture of a new generation of "energy-saving" injection molding machine has become an urgent problem to be concerned and solved.
At present, there are two solutions to the problem of energy saving of injection molding machine, i.e. all electric type and electric hydraulic hybrid type. Their main characteristics are as follows:
★ the all electric injection molding machine has a series of advantages, especially in precision and energy saving. According to reports, the power saving of the advanced all electric injection molding machine can reach 70%. In addition, due to the use of servo motor, the injection repetition accuracy of the injection molding machine is higher and the speed is faster. However, the service life of all electric injection molding machine is not as good as that of all hydraulic injection molding machine. At present, domestic manufacturers lack mature technology and use experience in all electric injection molding machine, and the market is still dominated by Japanese equipment.
★ electric hydraulic injection molding machine is a new type of injection molding machine that integrates hydraulic and electric drive. It combines the long life of full hydraulic injection molding machine and the energy saving advantages of full electric injection molding machine. This energy-saving injection molding machine combining electric hydraulic has become a leading direction of domestic injection molding machine technology development.
Terry machine has always been in the front end of the injection molding machine industry, independently designed and developed the electric hydraulic hybrid servo energy-saving plastic injection molding machine. Follow the high standard of European safety technology, more than 20% - 80% higher than the previous injection molding machine using pure hydraulic pressure in terms of power saving and water saving; the equipment operates stably, can be connected to the Internet, and has a fast cycle; the injection products have high repetition accuracy, and the injection weight is within plus or minus two thousandths, ensuring the best product quality and working efficiency; the professional oil circuit design makes the entire oil circuit free of pollution, all There is no oil leakage in the link to ensure the reliable operation of precision hydraulic components. Not only the energy consumption, noise level, oil quantity and maintenance requirements of the injection molding machine are reduced, but also the adaptability of the equipment to the products is increased, and the application occasions of the products with high precision requirements can be met.
The main key technologies used by the machine are:
● innovative and optimized design of five hinge toggle type die closing system is adopted to realize the opening and closing and locking of the die, which is characterized by fast die locking speed, low energy consumption and large die locking force.
The mold closing device of injection molding machine should ensure the reliability of mold closing, the flexibility of mold opening and the convenience and safety of product taking out, which is directly related to the quality and productivity of molded products. The toggle type closing mechanism, which uses the linkage mechanism to produce prestress, can realize the opening and closing and locking of the mold. It has the characteristics of fast mold locking speed, low energy consumption and large mold locking force.
● adopt full electric injection system, that is to say, the injection, pressure maintaining, anti salivation, pre molding and material storage actions in the molding process are realized by mechanical transmission of servo motor.
At present, the hydraulic injection system widely used in the market adopts low-speed and high torque hydraulic motor to achieve pre molding, hydraulic cylinder to achieve injection, pressure maintaining and anti salivation actions, and these actuators need hydraulic power system to provide power, which directly leads to the efficiency of the hydraulic power system directly affects the efficiency of these actions in these links. At the same time, the efficiency of the low-speed and high torque hydraulic motor itself is low, especially in the high-pressure and high-speed, the efficiency drops sharply, which seriously affects the efficiency of the whole machine, and the efficiency of the hydraulic cylinder itself is also a problem.
The all electric injection molding system adopted by this machine uses servo motor to drive through the synchronous belt to realize the pre molding and other actions. In this process, there is no efficiency problem of the hydraulic system. The efficiency of the servo motor and the synchronous belt drive is more than 95%, which ensures the effective use of energy and realizes the maximum energy saving.
The most effective measure for energy saving of hydraulic injection molding machine is the adaptive adjustment and matching of flow between the power mechanism and the actuator.
The high response AC servo motor drives the quantitative pump system to solve the problem of self-adaptive adjustment and matching of flow, and the low response speed caused by adjusting the speed of the hydraulic pump by the frequency conversion adjustment technology. At the same time, because of its high operating efficiency, it also improves the efficiency of power utilization. The speed of servo motor drive system changes with the flow demand of the system. The reaction speed is 4 / 1000 faster than that of servo valve. The hydraulic system basically does not need cooling water. For products with long pressure maintaining and cooling time, the energy saving can reach 80%. The pressure and flow are controlled by changing the speed of the motor.
Using this principle, not only there is no throttling loss, no need to control the auxiliary energy of the pump variable mechanism, but also can greatly reduce the energy loss of the pressure maintaining working condition and idling working condition (waiting period). When the pressure is maintained, the motor is almost stopped, and at the same time, the noise can be reduced, so it is very in line with the requirements of environmental protection.