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1. Obtain the necessary information

Analyze the co-constructed stamping processability based on relevant data, and conduct process review and standardization review on the workpiece.

1) Obtain product parts drawings with specific technical requirements. Understand the shape, size and accuracy requirements of the workpiece. The size of the key hole (size and position), the key surface, analyze and determine the reference plane of the workpiece.

In fact, the 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, comprehensive application of various stamping technologies, reasonable selection of stamping methods, correct stamping process formulation and mold structure selection, so that it can meet the product technology Requirements, but also in line with the conditions of the stamping process.

2) Collect process cards of workpiece processing. From this, it is possible to study the interrelationships between the preceding and following procedures, and the processing requirements and assembly relationships that must be mutually guaranteed between each procedure.

3) Understand the production batch of the workpiece. The production of parts plays a decisive role in the economics of stamping processing. For this reason, the type, structure, material and other related matters of the mold must be determined according to the production batch of the parts and the quality requirements of the parts, and the mold processing technology shall be analyzed accordingly. The economy and the rationality of public construction production, depict the outline of the stamping process.

4) Determine the specifications and roughness of the workpiece raw materials (such as sheets, strips, coils, scraps, etc.), understand the nature and thickness of the materials, and determine whether to take samples with less waste and no waste according to the manufacturability of the parts, and make preliminary determinations Material specifications and accuracy grades.

Under the premise of meeting the requirements of use performance and stamping performance, cheap materials should be used as much as possible.

5) Analyze the requirements of the material fiber direction and the direction of the burr in the design and process.

6) Analyze the technical capabilities and equipment conditions of the tool (mold) workshop to make molds and the conditions of the standard mold parts that can be used.

7) Familiar with the equipment information or situation of the stamping workshop.

8) Research and digest the above-mentioned information, and preliminarily conceive the structure of the mold. If necessary, s estions can be made to modify the established product design and process, so that product design, process, and mold design and manufacturing can be better combined to achieve more complete results.

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 processability analysis of stamping parts. it includes:

1) According to the shape feature, dimensional accuracy and surface quality of the workpiece, perform process analysis to determine its main attributes and determine the nature of the basic process. Basic processes such as blanking, punching, bending, deep drawing, flanging and bulging. List all the processes required for stamping. Generally, it can be directly determined from the product parts drawing requirements.

2) Determine the number of processes based on process calculations. For stretched parts, the number of drawing times should also be calculated. Bent parts and blanking parts should also be processed at one time or several times according to their shape, size and accuracy requirements.3) According to the deformation characteristics of each processing, the requirements of dimensional accuracy and the convenience of operation, the sequence of the process arrangement is determined. Such as the use of first punching and then bending, or bending first and then punching.4) According to the production batch, size, precision requirements, mold manufacturing level, equipment capacity and other factors, the single processes that have been initially arranged in sequence are combined with possible processes. Such as compound stamping process, continuous stamping process, etc. Generally, the stamping parts of thick material, low precision, small batch and large size should be produced in a single process, and simple molds should be selected; the stamping parts of thin material, small size and large batch should be continuously produced by progressive dies; and the shape accuracy For high stamping parts, composite molds should be used for stamping.

After determining the nature, sequence and combination of the processes, the stamping process plan is determined. That is to say, the structure of the mold in each process is determined.

3. Make necessary process calculations

1) Design the layout of materials and calculate the rough size.

2) Calculate the punching force (including the punching force, bending force, drawing force, flanging force, bulging force, and unloading force, pushing force, blank holder force, etc.). If necessary, the punching work and power must be calculated .

3) Calculate the pressure center of the mold.

4) Calculate or estimate the thickness of the main parts of the mold. Such as the thickness of the concave mold, the convex mold fixing plate, the backing plate, and the free height of the discharge rubber or spring.

5) Determine the gap between the convex and concave molds, and calculate the size of the working part of the convex and concave molds.

6) For the drawing process, it is necessary to determine the drawing method (with or without blanking), and calculate the number of drawing times and the size of the semi-finished product in the intermediate process.

For some processes, such as continuous drawing of strips, special process calculations are required.

Fourth, the overall design of the mold

On the basis of the above analysis and calculation, carry out the overall design of the mold structure (at this time, generally only need to draw a sketch), and initially calculate the closed height of the mold, and roughly determine the shape of the mold.

5. The structural design of the main parts of the mold

1) Part of the workpiece. Such as the design of the punch, the die, the punch and the concave die and the selection of the fixed form.

2) Positioning parts. There are many types of positioning devices commonly used in molds. Such as adjustable positioning plate, fixed stopper pin, movable stopper pin and fixed-distance side edge, etc., need to be selected and designed according to the specific situation.

In the continuous mold, it is also necessary to consider whether to use the initial stop pin.

3) Unloading and pushing device. For example, choose rigid or elastic, selection and calculation of spring and rubber, etc.

4) Guide parts. For example, choose guide post, guide sleeve guide or guide plate guide, choose middle guide post, side rear guide post or diagonal guide post, whether to use sliding guide sleeve or ball guide sleeve with steel ball, etc.

5) Supporting and clamping parts, fastening parts. Such as the selection of the structure of the mold handle and the upper and lower mold bases.

Six, select stamping equipment

The selection of stamping equipment is an important content of process design and mold design. The reasonable selection of equipment has a significant impact on the quality of the workpiece, the improvement of productivity, and the safety of operation, and it also brings convenience to the design of the mold.

The selection of stamping type mainly depends on process requirements and production batch.

The determination of the specifications of the stamping equipment mainly depends on the process parameters and the size of the mold structure. For crank presses, the following requirements must be met:

1) The nominal pressure of the press must be greater than the punching process force. which is

More precisely, it should be that the load curve of the stamping process must be below the allowable load curve of the press.For deep-drawn parts, the drawing work needs to be calculated.

2) The installation height of the press must meet the requirements of the closing height of the mould.

3) 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 in order to put in the blank and take out the workpiece.4) The size of the table surface of the press must be larger than the shape of the lower mold base, and there must be a fixed position for 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 scrap).

Seven, draw a general drawing of the mold

The general drawing of the mold (including the drawing of parts and workpieces) is drawn strictly in accordance with the drawing standards (GB/T4457~GB/T4460 and GB/T131-1993). At the same time, in actual production, combining the working characteristics of the mold and the needs of installation and adjustment, the layout of the drawing can form a certain habit.

Mold general drawing includes:

1) Main view. Draw a profile view of the mold in the working position. Under normal circumstances, half of them draw the blank placement before the punching start (when the punch slide is at the top dead center position); the other half draws the blank placement after the punching is finished, the workpiece is formed (or separated), and the punch slide is at the bottom dead center. The status of the location.

2) Top view. Usually half of the top view, the other half draws the top view of the top half. Sometimes the bottom half of the top view is completely drawn as needed.

3) Side view, bottom view and partial cross-sectional view, etc. If necessary, a side view of the working position of the mold must be drawn. Sometimes a bottom view and partial cross-sectional view of the upper part of the mold are drawn in the upper right corner of the drawing.

4) Workpiece diagram. The general workpiece picture is in the upper right corner. For the 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.

5) Layout drawing. For progressive dies, it is necessary to draw the layout method, process arrangement sequence and the stamping content completed by each step; the step spacing, the edge value, and the strip size should be marked. The layout drawing of the blanking die needs to indicate the layout method, strip size and the size of the edge value.

6) List the parts list, indicate the materials and quantity. All standard parts must be selected specifications.

7) Technical requirements and instructions. Technical requirements include punching force, selected equipment model, overall mold tolerance and assembly, installation and commissioning, mold closing height, mold clearance, and other requirements.

8. Draw parts diagrams of non-standard parts

All dimensions, tolerances and fits, shape and position tolerances, surface roughness, materials used and heat treatment requirements, and other technical requirements should be indicated on the part drawing.

Nine, fill in the mold record card and write the stamping process file

For small batch production, the process route list should be filled in; while for mass production, it is necessary to formulate process cards and procedure cards for each part.