Basic manufacturing process of metal containers - cold stamping technology

First, blanking process

Blanking is a stamping process that uses punches to separate materials, including blanking, punching, slitting, cutting, trimming, and trimming. However, under normal circumstances it often refers to blanking and punching. This process can be directly made of materials into parts, but also for bending, deep drawing and forming processes. Punching down a part or blank of a desired shape from a material is called blanking. Punching a hole of a desired shape on the workpiece is called punching.

1, punching process

(1) Elastic deformation.

(2) plastic deformation.

(3) fracture separation.

2, blanking die gap

(1) Determination of clearance value of blanking die

(2) Impact of Blanking Die Clearance on Blanking

3, convex and concave die edge size calculation

The dimensional accuracy of the die edge is the primary factor affecting the dimensional accuracy of the blank. The reasonable clearance of the die is also ensured by the die edge size and its tolerance.

4, punching force and its reduction method

(1) Calculation of punching force

(2) How to reduce the punching force

5, precision blanking

(1) Fine Emulsion

(2) Semi-precision

6. Renovation

(1) Rim renovation

(2) Inner hole renovation

Second, the bending process

1, bending deformation process

(1) Elastic bending stage.

(2) plastic bending stage.

2, the characteristics of the bending process

(1) The deformation zone is mainly located in the rounded part of the bending part, but no deformation occurs in the two sections far from the fillet area.

(2) In the bending deformation zone, (China Gold Packaging Network is a specialized technology trade website in the printing and canning industry), the tangential metal in the outer zone is stretched, and the tangential metal in the inner zone is compressed short. In these two deformation zones, there is a layer of metal with the same length, ie a strain-neutral layer.

3, the minimum bending radius

(1) The position of the strain-neutral layer. When punching sheets, to determine the minimum fillet radius of the punch and the blank of the bend

For the dimension, the position of the strain neutral layer must be determined first.

(2) Determination of the minimum bending radius. During the bending process, the fiber of the outer layer of the material is subjected to tensile stress. When the thickness of the material is constant, the smaller the bending radius, the greater the tensile stress.

4, bending rebound phenomenon

(1) Calculation of the rebound value. When the bending deformation is not affected by the external force, it is always accompanied by elastic deformation, so that the bending center angle and the bending radius become the same as the size of the mold, which is called rebound.

(2) Factors Affecting Springback Rate

1 mechanical properties of the material 2 bending deformation degree 3 bending center angle

4 Bending method 5 Workpiece shape 6 Mold structure

(3) Measures to reduce rebound

5, the bending process

The processability between bends refers to the requirements for the shape, size, and precision of the bent workpiece, and whether the material selection and technical requirements are in compliance with the technological requirements of the bending process.

(1) Bending radius of the bending piece

(2) The shape of the bend

(3) distance between edges of bent parts

(4) Straight edge height of bending parts

(5) Design process

Third, the deep drawing process

The flat blank is passed through a deep drawing die to form an open cylindrical or other cross-sectional shaped part, or a tubular or other cross-sectional shaped blank is reworked into a cylindrical or other cross-sectional shaped part. This process becomes deep drawing

(or drawing).

1, deep drawing process

(1) Female die flange section.

(2) The radius of the die radius This part of the material is not only radial tensile stress and tangential compressive stress, but also the compressive stress resulting from pressure, friction, and bending at the corners of the die. A transition zone.

(3) The wall portion.

(4) Punch rounded corners.

(5) The bottom part of the cylinder.

2. Mechanical analysis of deep drawing process

(1) Stress distribution in flange deformation area

(2) Analysis of wrinkling

(3) analysis of cracking problems

(4) Main measures to overcome cracking and wrinkling

3、Drawing coefficient and drawing times

When drawing up deep-drawing process procedures and designing deep-drawing dies, it is necessary to determine in advance whether the parts can be deepened by a deep-drawing process or multi-processes.

(1) Deep drawing coefficient

(2) Factors affecting the draw coefficient

(3) Deep drawing

(4) Deep drawing methods after the first deep drawing

4, the tensile part of the process and stretching process calculation

(1) Deep drawing process requirements

(2) Calculation of drawing process