The hydraulic control system of the bending machine press brake is composed of hydraulic control and sensor.Hydraulic control and energy conversion parts usually refer to hydraulic control valves, hydraulic pumps, etc. Hydraulic control technology is an important branch of automatic control system. Hydraulic control system has many obvious characteristics and many advantages in the bending machine system plays an important role.
Hydraulic control technology is a typical electro - hydraulic hybrid technology. Electric hybrid systems, for example, are powertrain based systems that combine mechanical, electronic and hydraulic systems. At present, hydraulic control system is widely used in equipment manufacturing, automobile industry, aerospace, metallurgy and other industries.
This paper introduces the electro-hydraulic control system of the bending machine in detail, which can be divided into open loop control system and closed loop control system. The beam of the bending machine is the main control part of the system.
1. The closed loop
The closed loop is also known as a feedback control system. The system compares the measured value of the system output with the expected given value, so as to produce the deviation signal, and then uses the signal deviation to control and adjust, so that the output value can be close to the expected value. While driving, for instance, the first person in the brain of the car driving direction have a preliminary perception, in the process of driving the car, the man in the car driving direction with eyes to observe and compare the car driving direction and the direction of the desired, constantly in the process to adjust the direction, finally make the car driving direction constantly close to the target direction, forming a closed loop control.
Closed-loop control is based on the operation of each part of the machine tool, with high accuracy and reaction speed. Because closed-loop control system involves many elements, compared with open-loop system, the whole system structure is more complex and the price is higher.
2. Open loop
Open loop is compared to closed loop, that is, open loop control does not feedback the current system control results. Like, throw things. Once something is thrown, there is no control over what is thrown. For as soon as things leave the hand, man's control over them ceases.
Therefore, in the open loop system of the bending machine, the accuracy of bending depends on the accuracy of each part of the machine tool. The system can not control and compensate the parameter changes in the bending process, resulting in low bending accuracy. Once the outside of the machine is disturbed, the internal parameters of the machine will change. However, in terms of system design, open loop design is simpler and more stable. Both the installation of early machine tools, and the maintenance of subsequent machine tools are more simple.