Metal stamping process

Bending: the plastic forming method of bending metal plates, pipe fittings and profiles into a certain angle, curvature and shape. Bending is one of the main processes widely used in stamping production. The bending of metal material is essentially an elastic-plastic deformation process. After unloading, the workpiece will produce elastic recovery deformation in the direction, which is called springback. Springback affects the accuracy of workpiece, which is the key technology to be considered in bending process.

Deep drawing: drawing, also known as drawing or calendering, is a stamping process method in which the flat blank obtained by blanking becomes an open hollow part by using a die. Thin wall parts with cylindrical, stepped, conical, spherical, box shaped and other irregular shapes can be made by deep drawing. If it is combined with other stamping processes, it can also make parts with extremely complex shape. There are many kinds of deep drawing parts in stamping production. Due to the different geometrical characteristics, the position of the deformation zone, the nature of deformation, the distribution of deformation and the stress state and distribution law of each part of the billet have considerable or even essential differences. Therefore, the determination method of process parameters, process number and sequence, and mold design principles and methods are different. According to the characteristics of deformation mechanics, various deep drawing parts can be divided into four types: straight wall revolving body (cylindrical part), straight wall non rotating body (box body), curved surface revolving body (curved surface shape part) and curved surface non revolving body.

Stretch forming is to apply tension to the sheet metal through the drawing die, which makes the sheet produce uneven tensile stress and tensile strain, and then the joint surface between the sheet metal and the drawing die gradually expands until it completely fits with the drawing model surface. Stretch forming is mainly applied to hyperbolic skin with certain plasticity, large surface area, gentle and smooth curvature change, and high quality requirements (accurate shape, smooth streamline and stable quality). Due to the simple process equipment and equipment used in stretch forming, the cost is low and the flexibility is high, but the material utilization rate and productivity are low.

Spinning is a kind of metal rotary processing technology. In the process of processing, the blank rotates with the spinning die or the spinning head rotates actively around the blank and the spinning die, and the spinning head makes the feed motion relative to the core mold and the blank, so that the blank has continuous local deformation and obtains the required hollow revolving body parts.

Shaping is to use the established shape of the grinding tool to carry out the secondary trimming of the product shape. It is mainly reflected in the pressure plane, spring foot, etc. In view of the elasticity of some materials and the one-time forming quality cannot be guaranteed, the second processing is adopted.

Bulging is a processing method that uses die to make sheet metal thin and increase local surface area to obtain parts. The common methods are rolling forming, cylindrical (or tubular) blank bulging and sheet blank stretching forming. Bulging can be realized by different methods, such as rigid die bulging, rubber bulging and hydraulic bulging.

Flanging is a plastic processing method that bends the material in the narrow-band area of blank edge or preformed hole edge into vertical edge along the curve or straight line. Flanging is mainly used to strengthen the edge of parts, remove trimming, and make parts assembled and connected with other parts or solid parts with complex special shape and reasonable space, and improve the rigidity of parts. In large sheet metal forming, it can also be used as a means to control cracking or wrinkling. Therefore, it is widely used in automobile, aviation, aerospace, electronics and household appliances.

Necking is a stamping method to reduce the diameter of the open end of the drawn flangeless hollow part or tube blank. Before and after necking, the end diameter should not change too much, otherwise the end material will wrinkle due to severe compression deformation. Therefore, necking from a larger diameter to a smaller diameter often requires multiple necking.