Why Need CNC Pressbrake Crowning Table For Metal Bending
CNC Pressbrake bending machine are widely used in sheet metal manufacturing to produce accurate and complex bend shapes. However, cutting edge technology and high-end automation demands for remarkably higher precision. The precision and tolerance requirements of fabricated products have increased recently, as there is always a need to produce parts with better performance and function. This is the reason why CNC metal bending machine requires a mechanical crowning table that is technologically advanced to compensate for errors and deliver better results. We will explain the importance of a mechanical compensation bending table and how it works on the CNC press brake to improve bending accuracy.
Why CNC Bending Machine Needs Mechanical Crowning Table?
Part of the CNC bending machine process is to calculate the bending angle, which is calculated based on the linear distance traveled by the workpiece, the angle of bending, and a range of factors such as the thickness of the material, its mechanical characteristics, and other environmental variables. However, these factors cannot be measured with 100% accuracy, and minute errors tend to accumulate, resulting in significant deviations or errors in the final product. This is where the mechanical compensation bending table comes in.
Structure of Mechanical Compensation Working table
The mechanical compensation bending table is made up of a range of mechanical blocks to achieve precise bending angles. The platform is detailed with a wedge that can be adjusted to compensate for error accumulation in the bending machine. The wedge's inclination can be adjusted to adapt to the type and thickness of material used in the bending process.
Working Principle of cnc controlled press brake bending crowning table
When the bending process is executed on the CNC bending machine, the distance measured between the inductive sensor and the stopper block is compared to the programmed value and adjusted according to the information provided by the mechanical compensation working table. The wedge tilts upward or downward, and the pressure applied to the workpiece also changes to compensate for inaccuracies and produce the ideal bending angle.
Improving Accuracy of Metal Bending on CNC Pressbrakes
The mechanical crowning table will enable the CNC bending machine to compensate for errors caused by various inaccuracies, improving the accuracy and quality of the bending process and products significantly.
Moreover, frequent maintenance and cleaning of the machine and the tools used will enhance the accuracy of the bending process. The machine should be calibrated regularly and keep in good working condition to ensure consistency and accuracy of the process.
Common Bending Accuracy Compensation Methods of European CNC Bending Machines
Currently, there are three standard methods used for compensating bending angle errors in CNC bending machines. These include: crowning, diagonal bending, and variable hydraulic crowning.
Crowning:
This method compensates for the bend angle error by altering the geometry of the punch and the die. This comprise of creating an asymmetric radius for the die base and by putting predetermined terms into the punch geometry. Crowning dependences on the width of the plate, thickness of the material, and the maximum bending force used in the operation.
Diagonal Bending:
The diagonal bending method involves varying the "displacement" parameters of the CNC machine. These displacements can be calibrated to produce an improved bending angle that matches the standard.
Variable Hydraulic Crowning Table:
This technique involves embedding a hydraulic system in the punch, which produces a precise angle, for producing a smooth and uniform bending operation.
The use of mechanical crowning table on CNC bending machines is essential to meet the tolerances and precision required by sheet metal fabrication today. While it is impossible to compensate for 100% of tolerances and accumulation errors, the mechanical crowning system is a significant improvement and a solution for producing precise products when compared to traditional press brake sheet metal bending machines. The future of CNC pressbrake will see continued development in technologies that enable higher quality, consistency, and optimal accuracy for sheet metal bending applications.
