The full servo motor on the CNC bending machine generally refers to the AC servo drive, and the motor controlled is a permanent magnet synchronous brushless motor, and the mainstream CNC bending machine adopts the following three driving methods.
Electro-hydraulic valve-controlled drive mode.
The hydraulic pump and hydraulic valve are used to provide the driving force, the hydraulic pump maintains the pressure, the hydraulic valve controls the flow rate and flow of the hydraulic oil, and the control system controls the machining accuracy of the bending machine by controlling the opening and closing time of the hydraulic valve. This control method leads to low machining accuracy of the bending machine, which is suitable for fields that do not require high machining accuracy.
At the same time, because the driving medium is hydraulic oil, the machining accuracy is also greatly affected by the temperature change of the hydraulic oil, and when the ambient temperature is low in winter, the machining accuracy and speed of the equipment are seriously affected; At the same time, after continuous work, the temperature of the hydraulic oil has increased significantly, resulting in a change in the pressure transmitted by the hydraulic oil, which affects the machining accuracy.
Therefore, when operating the electro-hydraulic VRLA bending machine, the operator will face a great challenge, the operator must not only understand the bending process, the applicability of the bending machine mold, the law of the bending sequence, but also understand the characteristics of the electro-hydraulic VRLA bending machine in terms of accuracy, in order to produce products with stable precision, so the electro-hydraulic VRLA bending machine has high requirements for equipment users.
Diesel-electric hybrid pump-controlled drive mode.
The servo motor is used to drive the piston pump to provide pressure, and the flow rate, flow direction and flow rate of the hydraulic oil are determined by the rotation direction and rotation speed of the servo motor, so that the pressure output of the hydraulic oil is more accurate, and the cylinder drive speed is faster, so that the machining accuracy and efficiency of the entire bending machine have been qualitatively improved. And because the piston pump hydraulic oil is used less, it has less impact on the temperature of the hydraulic oil, and the temperature change of the hydraulic oil is very low, and the impact on the accuracy of the bending process is also very low, which can keep the high precision of the press brake for a longer time. Moreover, the operator of the equipment does not have to worry about the impact of hydraulic oil on the bending accuracy, which reduces the requirements for the equipment operator.
All-electric servo drive.
The press brake driven by servo motor does not use hydraulic oil to transmit pressure at all, and there is no hydraulic system and hydraulic oil, so as to avoid the negative impact on accuracy and speed, so that the bending accuracy can always be maintained, and at the same time, it is more suitable for the ambient temperature and long-term high-load processing environment.
On the whole, in terms of machining accuracy, processing speed, stability and tolerance to the operator, the all-electric servo drive mode performs best, while the electro-hydraulic valve control drive mode loses in the comparison due to the inherent characteristics of hydraulic oil and hydraulic system.