The all-electric injection molding machine is gradually moving into people's field of vision with the development of precision injection products. The so-called all-electric injection molding machine refers to an injection molding machine that uses a servo motor to replace the original hydraulic device to complete the screw rotation, injection, and mold opening and closing processes. The mechanical principle of the all-electric injection molding machine is basically the same as that of the traditional hydraulic injection molding machine, except that the servo motor is used in the control part to replace the original hydraulic device. The injection device also includes two parts, plasticization and transmission. The plasticizing part is composed of screw, barrel, nozzle, and the transmission part is composed of ball screw, servo motor, transmission gear and clutch. The clamping device of the all-electric injection molding machine also has a toggle lever type and a direct pressure type, which is basically the same as the traditional precision injection molding machine.
By understanding the structure of electric injection molding machines, we can compare the performance differences between electric injection molding machines and hydraulic injection machines. Because the drive system of the electric injection molding machine does not use hydraulic oil, it eliminates the possibility of hydraulic oil leakage and the fluctuation of process parameters caused by the temperature changes of the hydraulic oil characteristic parameters. The ball screw has higher precision and better repeatability, which is conducive to the stability of processing. Using servo motor to control the plasticization of the screw, its measurement accuracy is higher, and it is more stable, and it is more conducive to speed regulation. Electric direct drive is also conducive to energy saving. However, this type of injection molding machine uses a servo motor to drive the ball screw to drive the screw for injection. Due to the heavy load of the ball screw and severe wear during high-speed rotation, the injection rate of the general all-electric injection molding machine is less than 500mm/s, which is all-electric A weakness of the injection molding machine.
The full hydraulic injection molding machine has many unique advantages in forming complex products, such as high mold clamping accuracy and large mold opening force. Its clamping device has a variety of structures, such as single-cylinder liquid-filled type, multi-cylinder liquid-filled type, and two-plate direct pressure type. There are many types and big differences. The single-cylinder liquid-filled injection machine is bulky, the hydraulic oil is easy to leak, the pressure rise speed is slow, and the energy consumption is high. The multi-cylinder liquid-filled injection machine alleviates and improves these problems to a certain extent. Its body is shorter and the volume is smaller. The two-platen direct pressure injection molding machine solves the above shortcomings. It has long mold opening and closing strokes, high efficiency, high mold adjustment and mold opening and closing precision, small clamping deformation, and easy mold replacement. However, its control technology is difficult, hydraulic Technology is also difficult to master.
Full hydraulic and full electric can be said to have their own characteristics. The all-electric injection molding machine is not as good as the all-hydraulic injection molding machine in terms of the accuracy of mold opening and closing and the service life, and the all-hydraulic injection molding machine must use a servo valve to ensure the accuracy, which will inevitably bring about an increase in cost. Nowadays, people are actively developing electric-hydraulic precision injection molding machines, and the metering and plasticizing process adopts electric drive to achieve energy-saving effect; hydraulic or electric-hydraulic compound clamping mechanism can also effectively maintain the accuracy and stability of processing. Therefore, the electric-hydraulic precision injection molding machine, which combines the energy saving of electric injection molding machine and the high performance of hydraulic injection molding machine, has become a new trend in the development of precision injection molding today.