1. The servo motor is used to directly drive the main oil pump of the hydraulic press to complete energy saving.
At present, there are still many difficulties in the direct drive of hydraulic pumps by high-power servo motors, mainly because the speed range of the hydraulic pump is very large, the minimum speed of the ordinary hydraulic pump is 600 r/min, and the hydraulic pump can work normally even below 10 r/min.
The presentation of high-power AC servo motor and its control technology High-power AC servo motor is a new product produced in the past 10 years. At present, the main technical application of switched reluctance motor (SMR), which has the advantages of simple and reliable, efficient operation in a wide speed and torque range, four-quadrant operation, fast response speed and low cost. Its defects are: large torque fluctuation and vibration; The system has nonlinear characteristics, high control cost, low power density, etc.
AC servo motor drive control unit is composed of a wide range of integrated circuits, high-power rectifier modules and other electronic power components. With the development of electronic technology, the performance of high-power AC servo motor drive control unit improves from time to time, and the price drops from time to time, which promotes the completion and implementation of high-power AC servo drive technology, and provides the possibility for the use of AC servo drive in the field of forging equipment. The focus of the seminar is to concentrate scientific research efforts and develop high-power AC servo motor control technology and related application technologies with independent academic property rights, so as to provide a solid foundation for the development of servo hydraulic presses.
2. After changing the speed of the servo motor, the closed-loop control of hydraulic pressure and position is completed.
After servo motor, the closed-loop control technology of hydraulic pressure and position of hydraulic press is not very mature. The traditional hydraulic press is controlled by proportional valve and proportional servo valve for hydraulic pressure and position stoppage. The special control algorithm of the demand study makes the hydraulic pressure have high stability and high precision between 1~25 MPa.
3. Discussion on energy recovery and energy management system.
In order to save energy and reduce energy loss as much as possible, it is necessary to reapply the potential energy of the slide to fall from its own weight and the energy generated by the pressure relief of the cylinder, which is currently not mature practice and experience in this regard. In terms of energy management, since the instantaneous power is many times greater than the uniform power, energy distribution should be done well in large servo hydraulic presses to prevent impact on the power grid.
4. Research and development of special control system.
Since most of the existing hydraulic presses are controlled by PLC, but the servo hydraulic press adopts hydraulic and speed closed-loop program control, the amount of computing is large, and it is difficult for ordinary PLCs to meet the needs. The control system of the servo hydraulic press adopts industrial PC stop control, and it is necessary to develop a special control system.
5. Optimization of forming process based on servo hydraulic press.
The data and shape of each stamping part are different, resulting in a completely different stamping process, such as the silent stamping process, and the control of the speed point is the key; For the reverse extrusion forming of magnesium alloy cups, the slide needs to experience 4 different speeds in one working cycle, of which the extrusion process is still controlled by constant pressure. Therefore, the servo hydraulic press only needs to be optimized with various forming processes to give full play to its advantages. It is important to study the forming mechanism of various forming processes and establish optimization parameters suitable for the molding process, so as to improve the production quality and consumption efficiency, and reduce the consumption cost.
6. Optimized design of servo hydraulic machine body.
Compared with traditional hydraulic presses, servo hydraulic presses have more elements to consider in the design of the fuselage due to their advantages of energy saving and noise reduction, mainly including various possible extreme working conditions, working frequency, and the complexity of stamping parts. For a long time, domestic engineering and technical personnel mainly use the experience method and similar product analogy method to stop the design, domestic forging machine tool products have large volume, heavy quality, poor control accuracy and other defects, steel consumption is one of the key elements of forging machine tool manufacturing enterprise product cost control.
After hard work, domestic scholars and engineering and technical personnel have developed relevant optimization software for the partial optimization of forging machine tool bed components, but they still mainly stay in the static design stage, do not think much about the dynamic processing process of the machine tool system, and the corresponding machine tool reliability problems have not been basically disposed of, which constitutes a reduction in the life of the machine tool and increases the maintenance cost of the machine tool. Therefore, the fuselage design requirements of servo hydraulic presses constitute the design methods and technical systems under the constraints of stiffness, strength and dynamic performance of forging machine tools, shortening the design and manufacturing gap with Xinglong national products.
