Electro-hydraulic servo CNC bending machine control system technology

Electro-hydraulic servo CNC bending machine control system technology

Electro-hydraulic servo bending machine has many advantages, among which the very prominent performance is the fast response, high output power and high control accuracy, so it is widely used in aviation, aerospace, military, metallurgy, transportation, engineering machinery and other fields. Electro-hydraulic servo technology is the best technical means to realize dynamic high circumference fatigue, programmable fatigue and low circumference fatigue, static constant deformation speed, constant load speed and various simulation systems.

Using electro-hydraulic servo valve to control the bending machine can achieve accurate and continuous pressure control, not only can the front-end pulse be output instantaneously, but also the output of triangle wave, square wave and sine wave can be controlled by computer, which greatly enhances the function of the fatigue testing machine. Not only dynamic fatigue test can be performed, but also static performance test of the test piece can be performed.

In addition, since the dynamic fatigue test uses an electro-hydraulic servo valve for load control, it can accurately control the output minimum test load and maximum test load without generating measurement errors of fatigue life due to inaccuracy of load output. However, the hydraulic servo parts processing accuracy is high, the price is high; sensitive to oil contamination, the reliability is affected; in the small power system, the hydraulic servo control is not as flexible as the electronic circuit control.

At present, the control technology of electro-hydraulic servo bending machine combines automatic control technology, hydraulic technology and microelectronics organically, which can form a new generation of servo valve products. From the domestic and international research, in order to adapt to the needs of high performance, high precision and automation of the system, electro-hydraulic servo control technology will develop towards the trend of standardization, virtualization, intelligence, digitalization, refinement and greening. And, with the development and progress of electronic equipment, control strategy, software and materials, electro-hydraulic control technology and servo valve products will make great progress in the integration of machine, electricity and liquid.

Servo electro-hydraulic CNC bending machine

The control system of electro-hydraulic servo bending machine is an important branch in the field of hydraulic technology, and is also one of the basic technical components of modern control engineering. In recent years, with the expansion of the demand for high response, high precision, high power, weight ratio and high power hydraulic control system in China’s manufacturing field, the research of electro-hydraulic servo control system in China has also made great progress.

Electro-hydraulic servo CNC bending machine control system can be classified from different perspectives, such as position control, speed control, force control, etc.; valve control system, pump control system; large power system, small power system; open-loop control system, closed-loop control system, etc. According to the different forms of input signal, it is divided into two kinds of analog servo system and digital servo system.

An electro-hydraulic servo system is a system that cannot have errors. When there is no offset between the displacement of the hydraulic cylinder and the displacement of the valve column, the system is at rest. Therefore, to overcome the working resistance and drive the hydraulic cylinder at a certain speed, it is first necessary to ensure that the slide valve has a certain valve opening, which is necessary for the electro-hydraulic servo system to work. The result of the hydraulic cylinder movement is always aimed at reducing this error, but it cannot be completely eliminated at any moment of its operation, and if there is no error, the servo system does not work.

Therefore, the basic principle of electro-hydraulic servo system is to compare the feedback signal with the input signal, output the deviation signal, and use this deviation signal to control the energy of the hydraulic energy input system, so that the system changes in the direction where the deviation becomes zero or equal to sufficient. The electro-hydraulic servo control system is characterized by a large power transfer density, which can constitute a small, lightweight and fast-responding high-power control unit.