CNC bending machine bending accuracy

CNC bending machine bending accuracy

In view of the structural characteristics and working conditions of the CNC bending machine, the following simplification principles are determined: 1.

1. For apparently will not affect the overall rigidity of the body, strength of the parts, such as screw holes, pin holes, rounded corners, etc. to be simplified, ignoring the outer and inner side plate for lifting convenience and installation of other devices and do the small hole.

2. The guide rail is seen as a free interface, no force transfer between the slider and the guide rail.

3. Consider the bottom plate ground bolt fixed as infinite stiffness, and the ground bolt and ground as fixed restraint.

4. Ignore the accessories that have less influence on the overall force condition.

5. Set the strength of the welded joint equal to the strength of the forgings.

6. Keep the detail structure of the dangerous parts

The purpose of these simplifications and modifications is to avoid small features and small structural components in the finite element meshing, generating a large number of finite element cells, increasing the computer’s computation time; and small features can also cause the mesh quality to decline, affecting the analysis accuracy of the structure. For this area of the hydraulic cylinder base plate model, considering that the force transfer is relatively complex, in the modeling process, in order to accurately obtain the stress value of the welded part of the hydraulic cylinder base plate and side plate, so the hydraulic cylinder is treated as a part of the model, which can be more convenient for loading processing.

The processability of the bent parts refers to the adaptability of the bent parts to the stamping process. Usually in the development of the stamping process plan, four-roller plate rolling machine manufacturers must consider the processability of the bent parts. Because the roll bending as a form of stamping process, it is necessary to briefly analyze several process indicators involving plate bending in this paper.

1. Bending accuracy

Bending accuracy mainly refers to the accuracy and stability of its shape and size, which is related to the mechanical properties of the sheet, thickness, forming tool structure and tool accuracy, the number of processes and the sequence of processes and the shape of the workpiece itself size and other factors. For the rolled plate, generally consider the roundness, cylindricity and misalignment, misalignment and other indicators within the design requirements after forming the cylinder section.

2. The minimum bending radius

When the relative bending radius r / t bending parts to a certain degree, will make the bending parts of the outer surface of the fiber tensile strain exceeds the allowed limit and cracking or fracture, so the bending parts have a minimum bending radius of the limit. In order to ensure that the outer surface of the plate fiber does not damage the premise, the workpiece can be bent into the inner surface of the minimum radius of the corner, called the minimum bending radius rmin, the corresponding rmin / t called the minimum relative bending radius.

Factors affecting the minimum bending radius are usually the mechanical properties of the material, the fiber direction of the material and the relationship between the direction of the bending line, the surface quality of the sheet and the quality of the section, the width of the bending sheet, the thickness of the sheet, etc. .