What are the elements of stamping die process design?

Stamping process design is the rational arrangement of raw material preparation, various processing procedures, etc., according to the requirements of the stamped parts, so that the stamping process is economically and technically reasonable and feasible. The process design includes the following aspects.

Process programme design

The process design is to initially determine the stamping process according to the characteristics of the shape and size of the stamped parts, the materials and the production batch, and to formulate several feasible processing solutions. Through comprehensive comparison of product quality, production efficiency, equipment conditions, mould manufacture and life, convenience and safety of operation and economy, the best process solution suitable for specific production conditions is determined.

Second process analysis

According to the requirements of the shape and size, material and precision of the product parts, the content of the processes identified in the design of the stamping process is analysed and calculated one by one to determine their adaptability to the stamping process.

Three process calculations

In order to carry out the design of the mould and the stamping process, the process calculation should firstly calculate the shape and size of the required blank according to the geometry and size of the product part, then draw up a reasonable layout plan according to the principle of saving materials and simplifying the mould structure, and determine the specifications of the plate or strip material and the way of feeding. The clearance between the convex die and the concave die is selected reasonably.

The stamping die is the main process equipment for stamping, and the stamping process is completed by the relative movement of the upper and lower dies. During processing, the upper and lower dies are continually divided and closed, so if the operator's fingers constantly enter or stay in the closed area of the die, it will pose a serious threat to his personal safety.

1. Materials commonly used in stamping The most commonly used materials in stamping production are metallic materials (including ferrous and non-ferrous metals), but sometimes non-metallic materials are also used. The main ferrous metals are ordinary carbon structural steel, high quality carbon structural steel, alloy structural steel, carbon tool steel, stainless steel, electrical silicon steel, etc.; non-ferrous metals are pure copper, brass, bronze, aluminium, etc.; non-metallic materials are cardboard, laminates, rubber plates, plastic plates, fibre plates and mica, etc. The supply state of metal materials for stamping is generally various specifications of sheet and strip material. The sheet material can be used for the production of engineering dies and the strip material (coil material) is used for the production of continuous dies. Sheet material is available in larger sizes and can be used for stamping large parts, or it can be cut into strips for stamping small and medium sized parts according to the dimensions of the layout; strip material (also known as coil material) is available in various sizes of widths, with an unrolled length of up to several tens of metres, supplied in rolls and adapted to automatic feeding for mass production in continuous moulds. For the grades, specifications and properties of the various materials, please refer to the relevant manuals and standards. 2. Rational selection of stamping materials The selection of stamping materials should take into consideration the requirements of the use of the stamped parts, the requirements of the stamping process and the economy, etc. (1) Reasonable selection of materials according to the requirements of the use of the stamped parts The selected materials should enable the stamped parts to work normally in the machine or parts and have a certain service life. For this reason, the selected material should meet the requirements of strength, stiffness, toughness, corrosion resistance and heat resistance according to the conditions of use of the stamped parts. (2) Reasonable selection of materials according to the requirements of the stamping process For any kind of stamped parts, the selected materials should be able to form stable and qualified products without cracking or wrinkling according to the requirements of the stamping process, which is the most basic and important requirement for material selection. For this purpose, the following methods can be used to select the material reasonably. ① Trial punching. Based on previous production experience and possible conditions, select several types of sheet material that can basically meet the requirements for the use of stamped parts for test punching, and finally select the one that has no cracks or wrinkles and whose scrap rate is low. The results of this method are more intuitive, but with a greater degree of blindness. ②Analysis and comparison. On the basis of the analysis of the nature of stamping deformation, the maximum degree of deformation during stamping and forming is compared with the ultimate degree of deformation allowed by the stamping and forming properties of the plate, and this is used as a basis for selecting the plate suitable for the stamping process requirements of the part. In addition, the same grade or the same thickness of the plate, there are cold-rolled and hot-rolled points. China's domestic plate, thick plate ( t>4mm) for the hot-rolled plate, thin plate (t<4mm) for the cold-rolled plate (there are also hot-rolled plate). Compared with the hot-rolled plate, the cold-rolled plate has precise dimensions, small deviations, few surface defects, brightness, dense internal organisation and better stamping performance. (Note: t generally stands for thickness in moulds, e.g. the thickness of a template, the thickness of a material can be expressed in terms of t.) (3) Reasonable selection of materials according to economic requirements The materials selected should be as inexpensive, convenient in origin and economical as possible to reduce the cost of the stamped parts on the premise that they meet the requirements of the use performance and stamping process