(1) Based on the workpiece drawing, analyze the shape characteristics, size, accuracy requirements, raw material dimensions, and mechanical properties of the workpiece, and combine factors such as available equipment and batch size. A good stretching process should ensure low material consumption, fewer processes, and less equipment usage.
(2) The calculation of main process parameters is based on the analysis of stamping process, identifying the characteristics and difficulties of the process, and proposing various possible stretching process plans according to the actual situation, including process properties, number of processes, sequence of processes, and combination methods. Sometimes there may be multiple feasible process plans for the same workpiece, and each plan usually has its own advantages and disadvantages. Comprehensive analysis and comparison should be conducted to determine the suitable and optimal plan.
(3) Process parameters refer to the data based on which the process plan is formulated, such as various forming factors (drawing coefficient, bulging coefficient, etc.), part unfolding dimensions, and various stresses. There are two situations for calculation. The first is that process parameters can be calculated more accurately, such as material utilization rate of part layout, workpiece area, etc; The second type is that process parameters can only be used for approximate calculations, such as general bending or deep drawing forming forces, complex component blank unfolding dimensions, etc. The determination of these process parameters is generally based on empirical formulas or charts for rough calculation, and some need to be adjusted through experiments.
(4) The selection of stretching equipment is based on the nature of the process to be completed and the force and energy characteristics of various equipment, taking into account the main factors such as required deformation force and size, and combining with the existing equipment situation to reasonably select the equipment type and tonnage.
