The bending length of the bending machine sheet material has a significant impact on the accuracy of the bent parts

It has been proven that the bending length of large bending machines has a significant impact on the accuracy of bending parts. The longer the plate of large bending machines, the greater the bending load required. Therefore, the inclination of the bending machine and the deformation of the slider also increase, making it more difficult to ensure accuracy.

Usually, the accuracy of the bending angle, including the total length of the bending, is referred to as "straight-line accuracy". If effective measures are not taken, the entry amount of the concave mold in the full length direction of the bent upper mold will be inconsistent, resulting in defects in the bent part. So it is necessary to use finite element simulation method to analyze the force and deformation displacement of the slider, extract and correct the deflection compensation curve, and use a driving motor or manual adjustment to achieve deflection compensation in the full length or local area, improving the linear accuracy of the large-sized bending machine.

The slider of a large bending machine is composed of welded steel plates of different shapes. During the modeling process, details that have little impact on the results are ignored, and only the main structure of the slider is retained. Due to the arbitrary 3D direction of the structure and its ability to adapt well to curved boundary models, it is possible to analyze the elastic deformation of the slider more accurately.

At the same time, it is necessary to fully consider the load and constraint application of the slider of the large bending machine. In actual working conditions, the slider of the large bending machine is always in motion. Due to the need for separate static analysis of the slider, it is necessary to simplify and approximate the constraints of the slider, and apply symmetric constraints to the nodes on the middle symmetry plane of the slider; The fixation of the slider is achieved by connecting the guide rail set on the frame with the rear of the slider, and applying full constraints at this position.

In addition, a surface load is applied to the contact area between the bottom of the hydraulic cylinder and the slider of a large bending machine. Due to the relatively small deformation of the slider in the vertical direction relative to its entire length, it belongs to elastic small deformation. Therefore, in the model, a uniformly distributed load is applied to the force bearing surface at the bottom of the slider; The bottom of the slider is connected to the upper mold by a connecting block, ensuring that force is evenly transmitted from the slider to the upper mold.

After in-depth analysis and setting the path, the deformation deflection curve of the force bearing surface at the bottom of the slider is extracted. The maximum displacement appears in the center of the slider and gradually decreases in a parabolic shape towards both sides. At the same time, the deformation displacement at any position in the bending length direction can be providing data support for designing wedges with different angles to form deflection curves.