Custom Precision Stamping And Drawing Dies For Oxygen Cylinders And Small Water Heaters

I. Stress Characteristics of Stamping Dies
During the stamping process, the forces borne by the die mainly include stamping force, side pressure, friction, and springback force. Stamping force is the main external force causing plastic deformation of the workpiece, directly determining the strength requirements of the die structure; side pressure and friction affect the die guiding accuracy and material flow state; springback force determines the dimensional accuracy and forming quality of the product. A comprehensive analysis of these stress factors is a prerequisite for the rational design of the die structure.

II. Calculation Method of Stamping Force
Stamping force is a key parameter in stamping forming, and its calculation accuracy directly determines the rationality of the die design. A commonly used estimation formula is as follows:

$$F = L × t × sigma_f$$
Where:

- $$F$$ is the stamping force, in Newtons (N);

- $$L$$ is the effective shearing or punching length, in millimeters (mm);

- $$t$$ is the workpiece sheet thickness, in millimeters (mm);

- $$sigma_f$$ is the material flow stress, in megapascals (MPa).

Flow stress is taken as the median of the material's yield strength and tensile strength, reflecting the material's comprehensive resistance during plastic deformation.

III. Consideration of Side Pressure and Friction Side pressure originates from the friction and compression of the material at the mold guide section, and its value is a certain proportion of the stamping force. Optimizing the friction coefficient can reduce side pressure, reduce mold wear, and extend mold life. Using lubricants and optimizing process parameters are the mainstream methods to achieve this.

The side pressure $$F_s$$ is calculated as follows:

$$F_s = \mu \times F$$ Where $$\mu$$ is the friction coefficient, determined according to the material surface condition and lubrication conditions, with a value range of 0.1~0.3.

IV. Verification of Mold Structural Strength After determining the stamping force and related stresses, it is necessary to perform force verification on key mold components to ensure that there is no plastic deformation or fatigue damage under stress. Using finite element analysis (FEA) software, combined with the calculated stress data, the stress distribution during mold operation can be accurately simulated, providing a basis for design optimization.

Choosing suitable mold materials and heat treatment processes to improve the mold's hardness, toughness, and wear resistance is an important guarantee for the mold to withstand high-intensity stamping pressure.