The bending deduction method and the bending compensation method (also known as the bending coefficient method) are bending calculation methods in sheet metal technology. The main differences between them are as follows:
Definition and calculation method:
Bending deduction method:
This is a simple algorithm describing the bending process, typically referring to the back-off amount. In this method, the flattened length (L) of the part is equal to the sum of the lengths of two theoretically flat sections extending to the "point of inflection" (the virtual intersection of the two flat sections) minus the bending deduction (A). Therefore, the total length of the part can be expressed as the equation L=L1+L2-A. If calculated using the outer dimensions + outer dimensions (including the thickness of the material), the corresponding coefficients need to be subtracted. This method is suitable for 90-degree bending unfolding calculations, especially for rough sheet metal work with low precision requirements.
Bending compensation method:
This method describes the developed length (L) of a part as the sum of the lengths of each segment after the part is flattened, plus the length of the flattened bend area. The length of the flattened bend area is represented as the "bend compensation" value (A). Therefore, the length of the entire part is expressed as the equation L=L1+L2+A. If calculated using internal dimensions + internal dimensions (dimensions excluding material thickness), corresponding coefficients need to be added. This method is suitable for non-90-degree bends, especially for development calculations where high bending accuracy is required.
Application Scenario:
The bend deduction method is more suitable for rough sheet metal work and situations where precision is not critical, such as the calculation of 90-degree bends.
The bending compensation rule is more applicable to situations where non-90-degree bends are required and high bending accuracy is demanded.
Considerations:
Both the bending deduction method and the bending compensation method require consideration of factors such as the type and thickness of the material, the radius and angle of the bend, the type of machine tool, and the step speed in practical applications.
In general, the primary differences between the bend deduction method and the bend compensation method lie in their calculation methods, application scenarios, and considerations. When selecting which method to use, it is necessary to comprehensively consider factors such as specific sheet metal part requirements, accuracy demands, and material characteristics.