Multi-Stage Hat-Shape Plate Forming for Uniform Thickness

The press forming process is divided into multiple stages: first forming a protrusion shape with curved surface, then forming corner portions by moving the plate, and finally correcting protruding portions to make them flat. This segmentation allows controlled thickness reduction at each stage, preventing fracture while achieving the required flat portions.

Before final flat portion formation, the plate is first formed with a protrusion shape having curved surface to distribute thickness reduction. Corner portions are then formed by moving the plate, creating preliminary conditions that prevent concentrated load during final flattening, thus avoiding fracture.

The forming process is segmented into multiple stages with progressive thickness reduction. Each stage reduces thickness uniformly across the plate, preventing localized stress concentration that would cause fracture in ultra-thin materials.

Different regions of the plate are treated differently during forming. The protrusion shape and corner portions are formed with specific curvature and movement patterns that ensure uniform thickness reduction in critical areas, maintaining strength while achieving weight reduction.

The complex requirement of uniform thickness reduction is achieved by segmenting the process into three manageable stages: protrusion shape formation, corner portion formation by plate movement, and protruding portion correction. Each stage has a specific function that contributes to overall uniformity.

The forming process uses periodic actions with different curvatures and plate movements at each stage. The curvature is adjusted periodically between stages, and the plate is moved periodically to different positions, creating a rhythmic process that achieves uniform thickness reduction through repeated controlled deformation.