3 Control system standardization

The control system of the rapid forging hydraulic press must meet the requirements of high speed, high reliability and dimensional accuracy control, and adapt to the very complex working environment of the forging site. The rapid forging hydraulic unit has a large structure, divided into multiple units on the ground and underground, and has many control and monitoring objects and complex actions. The control system needs to complete the interlocking and control of multiple signals of the unit, forging parameter setting, forging size position closed-loop control, etc. Multiple functions. The architecture of the control system has experienced the early digital control system, distributed control system and fieldbus control system. At present, the fieldbus control system based on industrial Ethernet is basically adopted. The control system has simple structure, flexible configuration, strong real-time operation and processing ability, and has good expansibility and compatibility, which truly realizes centralized monitoring, decentralized management and decentralized control.

The controllers of the control system of the fast forging hydraulic unit all adopt Siemens S7 series controllers. At present, S7 1500PLC controllers are generally adopted. The control bus has changed from Profibus DP fieldbus in previous years to Profinet industrial Ethernet control bus.

Many hydraulic technology companies and automation product companies have introduced related products that support Profinet interfaces, such as variable pump controllers, proportional valve controllers, various displacement detection sensors, operating master command handles, intelligent metering meters, etc. These components are directly detected, fed back and controlled through the Profinet bus. The control system has a simple structure, completely adopts digital detection and control, and has strong real-time performance and high reliability. The composition of the control system is shown in Figure 10.

4 Development trends

The rapid forging hydraulic unit comprehensively applies mechanical, hydraulic, electronic, automatic control, network communication, sensor detection, information processing, computer and software programming technology. It is a high-tech equipment of mechatronics and hydraulic integration, with high installed power and energy consumption. Large, complex technology and other characteristics. With the intensification of production competition, the requirements for the economy, reliability and production efficiency of the rapid forging hydraulic unit are constantly improving, and the development of various new technologies also promotes the continuous progress of the rapid forging hydraulic unit,

Constantly evolving.

At present, the main development trend of rapid forging hydraulic unit has the following aspects:

(1) Green design, development of high-efficiency and energy-saving fast forging hydraulic press group The fast forging hydraulic press group has fast forging speed and large output flow of hydraulic system. Previously, valve-controlled fast forging hydraulic press relied on various control valves for flow adjustment, resulting in large energy loss and energy waste due to valve orifice throttling. For example, several sets of fast forging hydraulic presses recently introduced by SMS, all the main pumps of the hydraulic system adopt proportional control variable pumps, and the operating speed of the hydraulic press is adjusted by the output flow of the proportional pump. When the hydraulic press is in a stopped state, it basically does not output flow. Minimize the energy loss of the system. Xinbeierkamp Intelligent Power System iPS (intelligent PowerSystem) controls the output of the proportional pump according to the working conditions to match the output flow with the action of the hydraulic press. Its patented drive system has proved in practice that its energy saving is as high as 30%. In the 35 MN high-speed forging hydraulic press unit developed by the author, the traditional plane layout of the hydraulic system of the unit is arranged in three dimensions according to the system function, which shortens the transmission distance of liquid pressure energy in the system, reduces the along-way loss and local loss in the transmission process, improves the transmission efficiency of pressure energy and improves the response speed of the hydraulic press. At the same time, the hydraulic system is equipped with some accumulators and superchargers, when working, the system works according to the superimposed liquid supply mode, reducing the number of main pumps, reducing the installed power and operating costs.

(2) Energy recovery and utilization to improve the energy utilization rate of the rapid forging hydraulic press unit The rapid forging hydraulic press unit is a large mass inertial load, and a variety of energy can be recovered and reused. For example, in 2018, DDS developed the first forging manipulator with Energy Recovery System (ERS). The energy recovery system helps to save up to 70% of the energy previously required to drive the machine, and the total energy consumed by the machine is reduced by 30%.

In the development of the rapid forging hydraulic unit, the author uses the hydraulic energy of the press to cool, eliminating the motor and hydraulic pump used for oil cooling in the system.

(3) Based on the condition monitoring system of big data, the intelligent predictive maintenance of fast forging hydraulic press is carried out. There are many components and components in the system of fast forging hydraulic press, which requires high reliability in the forging process. The condition of the unit is monitored and analyzed in real time, and the normal operation of the unit is ensured through predictive maintenance, downtime is reduced and the normal service period of the unit is prolonged.

For example, Oilgear company provides a set of intelligent monitoring and prediction solutions for fast forging hydraulic presses. It obtains data from pumps, valves and sensors of hydraulic systems, carries out state detection based on knowledge or data-driven analysis methods, carries out health assessment according to certain models, predicts the failure and remaining life of the unit, and realizes preventive maintenance. The condition monitoring system "magic eye" of Xinbeierkop rapid forging hydraulic press monitors the performance data of the hydraulic system: main filter, valve, seal, mechanical guide system, impact movement, auxiliary movement, main pump and high pressure pump, hydraulic medium, etc. based on big data analysis, promotes process optimization, risk control and predictive maintenance, and provides users with unit status and potential risk tips, preventive measures can be taken before potential risks arise, eliminating downtime, improving equipment utilization, and reducing maintenance costs.

(4) the development of program forging function, realize intelligent manufacturing, improve production efficiency, fast forging hydraulic unit can realize position control, automatic control according to the pass, and automatic forging of some more standardized forgings, which is an inevitable trend of technological development. When the rapid forging hydraulic press is used for program forging, it is necessary to develop intelligent forging process software, that is, the computer-aided intelligent forging system, which can automatically generate forging process data according to the initial state of the blank, the final forming size, material properties, etc.; When the control system performs automatic forging according to this process data, not only the required shape can be obtained, but also the internal organization and performance can meet the requirements.

SMS rapid forging hydraulic press is equipped with ForgeBase intelligent technology package, which can automatically generate forging pass data, which can make the press run automatically at the highest speed and cost-effectiveness; Wepuko PAHNKE's ForgeMaster software package fully takes into account the special requirements of its product range and ensures The best forging production plan. Because the forging pass data is closely related to the final tissue performance of the forging, the forging pass is generated simply according to the shape change, and the effect of the forging of multi-pass forging, different specifications, different materials, and different temperature ranges is very different, and the program forging application of the rapid forging hydraulic press is not ideal. There is still a lack of software packages in this area in China, and it is necessary to develop an intelligent forging pass generation process software package based on the influence of the internal organizational properties of forgings.

(5) Keep pace with the times and apply new technologies to improve the performance of the fast forging hydraulic press. The 31. 5/34. 0 MN fast forging hydraulic press that SMS will be put into operation in Germany in 2020 has installed a hydraulic valve block made of additive materials in the fast forging hydraulic press for the first time. 3D printing can not only design channels and optimize flow, but also reduce installation space and quality due to the more compact design.

5 Conclusion

After nearly 20 years of rapid development, the related technology is basically mature. The mechanical structure, hydraulic control technology and control system structure of the rapid forging hydraulic press have formed a standard mode. Many manufacturers have the ability to develop serialized products. China also has the strength to compete with foreign products. In the field of small and medium-sized rapid forging hydraulic presses, the market is basically owned by the country; in the field of large and medium-sized rapid forging hydraulic presses, although domestic products are also used, the selection of basic components, mechanical, hydraulic, and electrical systems are different from foreign countries. Big, but the main market is still occupied by foreign products. In the past five years, 12 sets of fast forging hydraulic press units (4 sets of SMS, 5 sets of Xinbeierkopp, 2 sets of Oilgear and 1 set of Wepuko PAHNKE) have been imported in China. The manufacturing technology, development of complete sets of products and technological innovation need to be further strengthened in China, so as to develop distinctive and competitive fast forging hydraulic press products.

Article quoted from: 0.13330/ j. issn.1000 3940.2023.11.001