Sheet Metal Bending and the Determinants of Bending Radius
The bending radius of sheet metal is a key factor that affects the bending coefficient. For example, a large bending radius requires a significant reduction in the bending coefficient, while a small bending radius allows for a smaller reduction. Today, we will analyze what determines the bending radius.
Factors Influencing the Bending Radius:
There are several factors that influence the bending radius of sheet metal, including the thickness of the sheet metal, the material of the sheet metal, the radius of the upper bending die, the lower bending die, the bending pressure, and the working temperature.
Bending Operations:
Sheet Metal Thickness: In practical work, it has been observed that the thicker the material, the larger the bending radius. We know that as the sheet metal becomes thicker, the bending pressure increases, and the groove width of the lower bending die increases. What factors could affect the bending radius?
Sheet Metal Material: Different materials have different bending coefficients for the same thickness, indicating that the material properties affect the bending radius. The material's ability to resist bending directly affects the bending radius. While the material does have an impact on the bending radius, it does not have a significant effect on our practical usage. We can create customized bending coefficient tables for different materials.
Factors Affecting the Bending Coefficient:
Radius of the Upper Bending Die: The normal radius of the bending die is not greater than 1. The minimum bending radius should not be smaller than 1. For non-specific requirements on the bending radius, the radius of the upper bending die does not have a significant impact. However, for special requirements where the bending radius needs to be smaller than 1 or much larger than 1, the radius of the upper bending die is no longer the determining factor. Therefore, the radius of the upper bending die directly affects the bending radius.
Bending Pressure: The thicker the sheet metal, the greater its resistance to bending deformation. In such cases, the bending pressure needs to be adjusted. The bending pressure cannot be infinitely increased and must be adjusted to an appropriate level. Bending pressure is directly proportional to the sheet metal thickness and inversely proportional to the width of the lower bending die groove. In actual bending operations, the sheet metal thickness is predetermined, and the width of the lower bending die groove is selected based on the sheet metal thickness. Therefore, the bending pressure is considered a constant determined by other factors. The bending radius does not need to consider the pressure factor.
Adjusting the Bending Die:
Lower Bending Die: The width of the lower bending die groove is related to the sheet metal thickness and has a corresponding relationship. In practice, the thicker the material, the larger the bending radius. For the same sheet metal thickness, different widths of the lower bending die groove result in different bending radii. This demonstrates that the width of the lower bending die groove is an important factor influencing the bending radius.
Working Temperature: The working environment temperature is usually at room temperature, so this factor does not need to be considered.
Setting Bending Parameters:
In summary, bending pressure is involved in the variation of the bending radius but is determined by the sheet metal thickness and the width of the lower bending die groove, so it is not considered. Almost all factors affect the bending radius, and we can only stabilize the influencing factors of the bending radius based on specific requirements.
For example, when the bending radius is not specified, all factors can be limited, and a specific bending coefficient table can be designated. When a large bending radius is required, the radius of the upper bending die can be modified to create a custom bending factor. The width of the lower bending die groove should not be changed arbitrarily as it affects both the bending radius and the bending coefficient. However, it can be utilized to modify the width of the lower bending die groove, thereby changing the bending coefficient and the bending radius.
