With the progress of technology and the increase of labor cost, the requirements of sheet metal processing, especially bending processing equipment, for processing efficiency and product quality are higher and higher.
In recent years, the national requirements for environmental protection are also becoming higher.
This post discusses the advantages of pure electric servo press brake compared with hydraulic press brake.
In recent years, the maturity of high-power and high torque servo motor and drive technology and the reduction of cost have promoted the application of relevant electric servo drive devices.
The NC press brake widely used in the sheet metal industry has opened a new trend that the pure electric servo main drive replaces the hydraulic main drive.
The tonnage and output of pure electric servo NC press brake are increasing.
This post expounds the advantages of pure electric servo press brake compared with hydraulic press brake from the aspects of energy-saving, environmental protection, processing efficiency, bending accuracy and maintenance cost.
1. Significant energy saving
One of the advantages of pure electric servo drive technology is that the input power of the motor is directly proportional to the load power.
The power consumption during bending is large, the power consumption during no-load upward movement of the ram is small, and there is basically no power consumption when the ram stops.
However, the main motor and hydraulic pump of the hydraulic servo press brake continue to operate even if the ram does not work, and consumes electric energy.
In addition, the mechanical main transmission efficiency of pure electric servo press brake is more than 95%, the hydraulic transmission efficiency of hydraulic servo press brake is less than 80%, and the efficiency of hydraulic system components is lower after aging and wear.
Taking the 100t press brake as an example, the power consumption of the main machine of the pure electric servo press brake is about 12 kwh/d, while the power consumption of the hydraulic system of the hydraulic press brake is about 60 kwh/d, and the energy-saving of the pure electric servo press brake is about 80%.
2. Environmental protection and no pollution
The pure electric servo press brake does not use hydraulic oil, so there is no trouble in replacing hydraulic oil and removing hydraulic components, no leakage of hydraulic oil in the process of replacement, removal and replacement and daily system, and no waste oil treatment and pollution.
3. The ram has fast speed and high production efficiency
The response speed of the servo motor is faster than that of the hydraulic servo.
Taking the 100t pure electric servo press brake as an example, the return and fast down speed of the ram is up to 200mm/s and the working speed is 0 ~ 20mm/s;
The return and fast down speed of the ram of most hydraulic press brakes of the same tonnage are less than 120mm/s and the working speed is 10mm/s.
The hydraulic servo press brake is affected by the environment and the heating of the hydraulic system, so it needs to be started for preheating or shut down for heating;
Once there is a fault in the hydraulic system, the technical requirements for troubleshooting are high, the time is short, and the components of the pure electric servo press brake are few, and the failure rate is very low.
These problems do not exist fundamentally. Therefore, the processing efficiency of the pure electric servo press brake is nearly twice that of the hydraulic press brake of the same tonnage.
Fig. 1 Comparison of daily total energy consumption of press brake
Fig. 2 Comparison of fast up and down speeds of press brake
4. High bending accuracy
The bending speed of the pure electric servo press brake is adjustable.
It can set and adopt a more appropriate bending speed for different thicknesses, different materials and different bending lengths, so as to improve the bending accuracy and maintain high productivity.
The deflection compensation shaft of pure electric servo press brake adopts ⅶ a structure compensation device, which has higher bending accuracy.
The bending angle error of the hydraulic press brake is within ± 1 °, while the main drive of the servo press brake drives the lead screw through the servo motor, which has higher transmission accuracy.
By measuring the bending angle of various specifications of plates, the bending angle error can be well guaranteed to be within ± 0.5 °.
5. Low maintenance cost
The hydraulic oil of the hydraulic press brake needs to be replaced regularly;
Pumps, valves and seals are easy to fail and damage and the hydraulic system is easy to be polluted. It is difficult to find and eliminate faults. Once the hydraulic system is polluted, it is difficult to clean the system and will cause environmental pollution.
The transmission system of pure electric servo press brake is simple, basically has no maintenance cost, and only needs regular lubrication.
The design and manufacture of the electric servo press brake aim at high bending precision, high operation efficiency and high reliability.
The finite element analysis of the bed and ram is carried out to optimize and strengthen the rigidity of the bed and ram.
According to the analysis of energy consumption, environmental protection, processing efficiency, processing accuracy and cost of pure electric servo press brake and hydraulic press brake, the conclusions are shown in the attached table.
Comparison between hydraulic press brake and electric servo press brake
|Comparison category||Hydraulic press brake||Electric servo press brake|
|Energy consumption (taking 100t press brake as an example, calculated as 8h per day)||The power consumption is about 60kwh/d.||The power consumption is about 12kwh/d.|
|Environment protection||Possible pollution||No pollution possible|
|Processing efficiency (take 100 press brake as an example)||The return and fast lowering speed of the ram is less than 120mm/s, and the working speed is 10mm/s.||The ram travel and fast down speed are up to 200mm/s, and the working speed is 0 ~ 20mm/s.|
|Machining accuracy||The bending angle error is within ± 1 °.||The bending angle error is within ± 0.5 °.|
|Cost||Slightly lower||Slightly higher|