Stamping dies have always been an important part of Home Appliances and Auto Parts. The quality of die design and production will affect the use of the final product. The 9 core designs of stamping dies play a decisive role in the overall performance of the product.

1. Obtain necessary information. Analyze the stamping processability of the workpiece based on relevant information, and conduct process review and standardization review on the workpiece.

A. Obtain product part drawings with specific technical requirements. Understand the shape, size, and precision requirements of the workpiece. Analyze and determine the dimensions (size and position) of key holes and key surfaces, and the reference surface of the workpiece. In fact, the various process requirements of stamping parts are not absolute. Especially in the current situation of rapid development of stamping technology, according to the actual needs and possibilities of production, various stamping technologies should be comprehensively applied, stamping methods should be reasonably selected, stamping processes should be correctly formulated, and die structures should be selected, so that they can meet both the technical requirements of the product and the conditions of the stamping process.

B. Collect the process cards of workpiece processing. This can be used to study the relationship between the previous and subsequent processes and the processing requirements and assembly relationships that must be guaranteed between the processes.

C. Understand the production batch of workpieces. The production of parts plays a decisive role in the economy of stamping processing. Therefore, the form, structure, material, and other related matters of the mold must be determined based on the production batch and quality requirements of the parts, and the economy of the mold processing technology and the rationality of public construction production can be analyzed to outline the stamping process.

D. Determine the specifications and rough material conditions of the workpiece raw materials (such as sheet materials, fillers, coils, waste materials, etc.), understand the nature and thickness of the materials, determine whether to use less waste samples based on the processability of the parts and preliminarily determine the specifications and accuracy levels of the materials. Under the premise of meeting the performance and stamping performance requirements, cheap materials should be used as much as possible.

E. Analyze the requirements of the design and process for the direction of the material fiber and the direction of the burrs.

F. Analyze the technical capabilities and equipment conditions of the tooling workshop for manufacturing molds and the situation of the standard mold parts that can be used.

G. Be familiar with the equipment information or situation of the stamping workshop.

H. Study and digest the above information and preliminarily conceive the structural plan of the mold. If necessary, make modification suggestions for the established product design and process to better combine the product design, process and mold design, and manufacturing to achieve a more perfect effect.

2. Determine the process plan and mold structure type. The determination of the process plan is the most important link that should be carried out after the process analysis of stamping parts. It includes:

A. According to the shape characteristics, dimensional accuracy, and surface quality requirements of the workpiece, process analysis is carried out to determine its main attributes and determine the nature of the basic process. That is the basic processes such as blanking, punching, bending, drawing, flanging, and bulging. List all the single processes required for stamping, which can generally be directly determined from the product part drawing requirements.

B. Determine the number of processes based on process calculations. For stretched parts, the number of stretches should also be calculated. And bent parts and punched parts should also be determined to be processed once or several times based on their shape, size, and accuracy requirements.

C. Determine the order of process arrangement based on the deformation characteristics of each processing, dimensional accuracy requirements, and the convenience of operation. For example, whether to use punching first and then bending, or bending first and then punching.

D. According to various factors such as production batch, size, accuracy requirements, mold manufacturing level, equipment capacity, etc., the single processes that have been preliminarily arranged in sequence are combined into possible processes. Such as compound stamping process, continuous stamping process, etc. Usually, thick material, low precision, small batch, large size stamping parts should be produced by a single process, and simple molds should be selected; thin material, small size, large batch stamping parts should be produced continuously by progressive molds; and stamping parts with high shape and position accuracy should be stamped by compound molds.

After determining the nature, sequence and combination of the process, the stamping process plan is determined. That is, the structural type of the mold for each process is determined.

3. Perform necessary process calculations

A. Design the material layout and calculate the blank size.

B. Calculate the punching force (including blanking force, bending force, drawing force, flanging force, bulging force, unloading force, pushing force, pressing force, etc.), and if necessary, calculate the punching work and power.

C. Calculate the pressure center of the mold.

D. Calculate or estimate the thickness of the main parts of the mold. Such as the thickness of the fixed plate and pad of the die and the free height of the unloading rubber or spring.

E. Determine the gap between the convex and concave dies and calculate the size of the working parts of the convex and concave dies.

F. For the drawing process, it is necessary to determine the drawing method (pressing or not pressing), and calculate the number of drawing times and the size of the semi-finished products in the intermediate process.

For some processes, such as continuous drawing with material, special process calculations are required.

4. Overall design of the mold

Based on the above analysis and calculation, the overall design of the mold structure is carried out (generally only a sketch is needed at this time), and the closing height of the mold is preliminarily calculated, and the outer dimensions of the mold are roughly determined.

5. Structural design of main parts of the mold

A. Parts of workpiece. Such as the design of structural forms such as punch, die, punch, and die, and the selection of fixing forms.

B. Positioning parts. There are many types of positioning devices commonly used in molds. Such as adjustable positioning plates, fixed stop pins, movable stop pins, and fixed-distance side blades, etc., which need to be selected and designed according to specific conditions. In continuous molds, it is also necessary to consider whether to use initial stop pins.

C. Devices for unloading and pushing parts. Such as whether to choose rigid or elastic, the selection and calculation of springs and rubbers, etc.

D. Guide parts. Such as whether to choose guide pins, guide sleeves, or guide plates, whether to choose intermediate guide pins, side and rear guide pins, or diagonal guide pins, whether to use sliding guide sleeves or guide sleeves with steel balls, etc.

E. Support and clamping parts, fastening parts. Such as the selection of structural types of mold handles, upper and lower mold bases, etc.

6. Select stamping equipment

The selection of stamping equipment is an important part of process design and mold design. Reasonable selection of equipment has a significant impact on the quality assurance of workpieces, the improvement of productivity, and the safety of operation, and also brings convenience to the design of molds. The selection of stamping type mainly depends on the process requirements and production batch. The determination of stamping equipment specifications mainly depends on process parameters and mold structure dimensions.

For crank presses, the following requirements must be met:

A. The nominal pressure of the press must be greater than the process force of stamping. More precisely, the load curve of the stamping process must be below the allowable load curve of the press. For deep drawing parts, the drawing work must also be calculated.

B. The die height of the press must meet the requirements of the die closing height.

C. The stroke of the press must meet the requirements of workpiece forming. For the press used in the deep drawing process, its stroke must be greater than 2~2.5 times the height of the workpiece in the process, so as to put in the blank and take out the workpiece.

D. The table size of the press must be larger than the outer dimensions of the lower die seat of the mold, and there must be a position for fixing the mold. Generally, each side is larger than 50~70mm. The size of the leak hole on the press table must be larger than the size of the workpiece (or waste).

7. Draw the general drawing of the mold. The drawing of the general drawing of the mold (including the part workpiece drawing) is strictly in accordance with the drawing standards. At the same time, in actual production, combined with the working characteristics of the mold and the need of installation and adjustment, the layout of its drawings forms a certain habit.

The general drawing of the mold includes a main view. Draw a cross-sectional view of the mold in the working position. Generally, half of it draws the situation of the blank being placed before the start of stamping (when the punch slider is at the top dead center); the other half draws the state after the stamping is completed, the workpiece has been formed (or separated), and the punch slider is at the bottom dead center.

b top view. Usually, half of the top view is drawn, and the other half draws the top view of the upper half. Sometimes the top view of the lower half is also drawn completely as needed.

c side view, bottom view partial section view, etc. If necessary, a side view of the mold working position must be drawn. Sometimes a top view of the upper half of the mold and a partial section view are also drawn in the upper right corner of the drawing.

d workpiece drawing. Generally, the workpiece drawing is drawn in the upper right corner. For work completed by several sets of molds, in addition to drawing the workpiece drawing of this process, it is also necessary to draw the workpiece drawing of the previous process.

e. Layout drawing. For progressive molds, it is necessary to draw the layout method, process arrangement sequence, and stamping content completed in each step; the step spacing, overlap value, and strip size should be marked. The layout drawing of the punching dies needs to mark the layout method, strip size, and overlap value.

f. List the parts list, and indicate the material and quantity. All standard parts must select specifications.

g. Technical requirements and instructions. Technical requirements include punching pressure, selected equipment model, overall mold shape and position tolerance and assembly, installation and debugging, mold closing height, mold clearance, and other requirements.

8. Draw the parts drawings of each non-standard part

The parts drawings should indicate all dimensions, tolerances and fits, geometric tolerances, surface roughness, materials used, and their heat treatment requirements, as well as other technical requirements.

9. Fill in the mold record card and write the stamping process file

For small-batch production, the process route list should be filled in; for large-scale production, a process card and process card should be prepared for each part.