How to deal with common problems in the processing of drawing molds?

1. In terms of the original data of the molded workpiece, after the appearance processing of the original data, such as phosphating, spraying or other appearance processing, the appearance of the molding data forms a layer of non-metallic mold, which can greatly reduce or eliminate the strain of the workpiece. . This approach is often costly and requires additional production equipment and production processes. While this method is sometimes effective, it is rarely used in actual production.

2. Adding a layer of polyvinyl chloride and other films between the metal parts and the mold, between the mold and the forming data can sometimes solve the problem of workpiece strain. For the production line to continuously supply the film through the organization, for the stamping equipment for periodic production, each production part needs to add the film, which affects the productivity. The overall cost of this method is also high and a lot of waste is generated. This method can be used for the production of small batches and large workpieces. In the case of very small forming load, sometimes lubricating oil or lubricating oil with EP additives can solve the problem of workpiece strain.

3. In terms of mold, the mold is convex. Die data or die convex. Manipulate the appearance of the die or select the appropriate die data to change the nature of the contact between the drawing data and the punch. Practice has proved that this is an economical and practical strain treatment method, and it is also a method widely used at present. To sum up, deal with deep drawing and workpiece as well as die convex. There are many ways to strain the appearance of a die. For detailed cases, the selection should be based on artifacts and negative sizes. mass production. Type of processing data, etc.

The shape of the drawing piece is complex and diverse, and the dimensional accuracy is required to be high. The processed product is on the same level as the cut product, and the processed cut surface is flat. It’s very smooth and bright. It is more difficult to machine than other crafts. It can process gear fine-blanking parts with small modulus and high precision, and the drawn parts have clear outline and small slump angle. Drawing parts mainly rely on the pressure of the press to process metal or non-metal data through the die. The workpieces processed by drawing parts have high precision and can reach the micron level. Compared with other workpieces, it has the advantages of light weight, thin thickness, uniform distribution and strong pressure resistance. In the process of processing, large-scale production, shortening processing time, one-time molding, no need for other processing. Mainly used in automobile brakes, automobiles, motorcycles and other products. It is an economical and fast electromechanical product.

Let’s popularize some questions about stretch pieces so you can gain some expertise by learning to understand them clearly.

1. Blanking – deep drawing, suitable for shallow drawing or deep drawing?

Blanking-Drawing is suitable for shallow drawn parts, because the steel plate is compressed during blanking and the steel plate is also compressed during deep drawing. Therefore, on this basis, the above-mentioned corresponding theory will appear. There is no doubt about that.

2. How to roll the thread on the stretched part?

In this case, in the opinion of the manufacturer of stretched parts without Xizhongnan lighting fixtures, because it is not applicable, the general rolling method cannot be used, but a mandrel is first passed through the stretched part, and then the rolling can be successfully completed operate.

3. How to prevent the stretched parts from pulling?

In order to prevent hair problems in stretched parts, there are approaches we can take that may be noticed. The main points are as follows:

First, the die used has a smooth appearance and should be smooth when drawing.

Second, the hardness of the mold material should not be too low.

Third, do a good job of cleaning the stretched parts, and there should be no dust and dirt.

For stretched parts, the above problems can be said to be very important and basic. I have never done it before. I hope everyone can study and understand carefully, so as to master them in time, and gain something, develop, and develop in the process of product learning. Breakthrough.

The above is about the processing dies of stretched parts, as well as some common sense of the processing of stretched parts. Many customers actually know a little when they choose the manufacturer of stretched parts, so it is easy to be ignored in many professional issues. But this is the professional side of the tensile parts processing factory, and it is recommended to choose carefully. Hope the above content can be helpful to readers.

What are the types of processing shapes of stainless steel drawing parts?

Simply put, drawing is a stamping method in which a flat blank is formed into an open hollow part with a die. Thin-walled parts with irregular shapes such as cylindrical, rectangular, stepped, spherical, conical, and parabolic shapes can also be combined with other stamping processes to produce parts with more complex shapes.

According to the characteristics of deformation mechanics, stainless steel tensile parts can be divided into box-shaped parts (straight-wall non-rotating body), circular simple-shaped parts (straight-wall rotating body), surface-shaped parts (referring to curved surface rotating body) and non-rotating surface forming Components. It is characterized by:

First, the deformation characteristics of cylindrical parts.

In the deepening process, the deformation area is the blank flange edge, and the other parts are the force transmission area, which does not participate in the main deformation; under the action of tangential compressive stress and radial tensile stress, the blank deformation area produces tangential compression and radial tension. The deformation of the extension; the extreme deformation parameters are mainly limited by the bearing capacity of the blank force transmission area.

Second, the deformation characteristics of the box.

Its deformation properties are the same as for circular simplified parts. The difference is that the deformation that is always stretched and compressed is unevenly distributed around the blank, the rounded corners have large deformation, and the straight edge has small deformation; there is an interaction between large and small deformations around the blank.

3. Deformation characteristics of curved surface shape parts.

The periphery of the blank is the tensile deformation area that has been under compression, and the middle of the blank is the expansion deformation area of ​​bidirectional tensile stress.

4. Deformation characteristics of non-rotating body curved parts.

The deformation area of ​​deepening the blank is also composed of the outer deepening deformation area and the inner expansion deformation area, but the distribution of these two deformations around the blank is uneven; when the flange edge of the surface is partially deepened, the deformation area around the blank also has shearing deformed.

The above is the processing appearance type of stainless steel drawing parts. In the processing of drawing parts, quality is an important issue that cannot be ignored. No matter what type of drawn part, material, process and die are important factors that affect the deep drawing process. Hope the above content can be helpful to readers.

What are the factors that affect the quality of drawing die processing?

1. Materials: Good materials are half the battle. Stretching cannot be ignored. Cold rolled steel plate is mainly composed of 08Al.08.08F.10.15.20 steel, of which 08 steel is the most widely used, divided into boiling steel and killed steel. The price of boiling steel is low and the surface quality is good, but the segregation is serious and there is a tendency to adapt to aging. Not suitable for parts with high stamping performance and strict appearance requirements.

2. Determination of blank size: The blank diameter of a simple rotating body drawing part does not become thinner during the drawing process. Although the thickness of the material has changed, it is basically very close to the original thickness. It can be calculated according to the principle of the area of ​​the blank and the area of ​​the drawn part (if there is trimming, the trimming allowance must be increased. However, the shape and process of the deep-drawn part are often complicated, sometimes thinning and stretching. Although there are many three-dimensional The software can calculate the material, but its accuracy is less than 100%.

The solution: material testing. A product part should go through multiple processes, the first of which is usually the process of material transportation.

First perform material calculations to have a rough idea of ​​the shape and size of the blank to determine the overall dimensions of the material delivery die. After the mold design is completed, do not deal with the convex and concave die dimensions of the material conveying die. First use wire cutting and machine the blanks (when the blanks are large, they can be milled with a milling machine and then repaired). After trial and error in the subsequent stretching process, half the size of the feed conveyor die was finally determined.

3. The drawing coefficient m is one of the main process parameters in the calculation of the drawing process, and is often used to determine the drawing sequence and drawing times. There are many factors that affect the elongation coefficient m, including the properties of the material. The relative thickness of the material. Drawing method (with or without a blank holder). number of stretches. stretching speed. Punch and concave die fillet radius. The calculation and selection principle of the tensile factor m is the focus of introduction in various stamping manuals, including calculation. View the form. calculation and many other methods.

The relative thickness of the material. Drawing method (with or without a blank holder). In the process of mold repair, the number of stretches is not easy to adjust, so be careful! When you choose the stretch factor m, it is better to find another colleague. Grease the concave die or place a film bag on the sheet.

4. When stretching and cracking, apply lubricating oil on the die (do not apply it on the punch), and cover the plastic film of 0.013-0.018 mm with the die.

5. During the stretching process, due to the cold plastic deformation, the parts are cold hardened, the plasticity is reduced, the deformation resistance and hardness are increased, the mold design is unreasonable, and intermediate annealing is required to soften the metal and restore the plasticity. Note: annealing is not necessary in the general process. After all, in order to increase the cost, choose to increase the process and increase the amount of annealing, and use it with caution! Annealing generally adopts low temperature annealing, that is, crystallization annealing.

Two points should be noted during the annealing process: carbon and oxidation. It’s mostly about oxidation. Oxidized skin has two hazards: thinning the effective thickness of the workpiece and increasing die wear. When the company’s conditions are not met, ordinary annealing is generally used. To reduce the production of oxidized skin, the furnace should be filled as much as possible during the annealing process. I also used the soil method: 1. The workpiece can be mixed with other workpieces (premise: the annealing process parameters should be basically the same) 2. The workpiece is put into the iron box for welding, and then the electric furnace is installed. To eliminate scale, the furnace should be filled as much as possible during the annealing process.

When the company conditions are met, nitrogen furnace annealing, that is, bright annealing, can be used. Don’t look closely, it’s almost the same color as it was before annealing. Add the intermediate annealing process when there is no other way to deal with cracks in cold-hardened metal or die tests.

The above is about the mold processing of the drawn parts. When judging the cause of cracks in the processing of tensile parts, it can be referred to: the cracks caused by poor material quality are mostly serrated or irregular in shape, and the cracks generated by the process mold are generally neat. To ensure wear resistance and prevent tensile scratches, punches and dies and blank holders must be hardened and, if necessary, plated with hard chrome. Hope the above content can be helpful to readers.

What are the common quality problems of stamping and drawing parts processed by stamping dies?

1. During the stretching process of the wrinkled material, the tangential stress of the surrounding edge part is too large, which causes the instability of the material and causes the product to form uneven wrinkles along the tangential direction of the edge, which is called wrinkling. When the wrinkling is serious, it will also cause the material to be difficult to pass through the gap between the die and the punch during the stretching process, the tensile deformation force will increase, and even lead to cracking. The occurrence of buckling depends not only on the tangential stress at the edge of the material, but also on the thickness of the tensile member. Generally speaking, the stretching die using nitrogen gas spring or excellent release glue has better effect, and it is not easy to appear wrinkling, cracking and other phenomena. Why? Since the force of the nitrogen gas spring or super glue is generally balanced, there is no problem of uneven force. Nitrogen gas springs are better than Uniglue, because the nitrogen springs have strong force and good balance, but the price is several times more expensive than Uniglum, and many factories cannot afford them. Generally, only slightly larger factories can afford to use gas springs. If you use it for a long time, the super glue will shrink and its strength will not be as strong as it used to be. You’ll have to get a new one, but it’s a lot less expensive than a gas spring. The blank holder ring can be used to prevent wrinkling. In some places, it is called a pressing rib, which means that a circle of raised ribs is placed around the material without affecting the post-processing of the product, commonly known as a pressing rib, to press the material. Around. The advantage of this is that the stretched product will be fuller and will also prevent wrinkling.

The blank holder force needs to be relatively adjusted in the mold test. The general design is not so reasonable, and the height of the blank holder needs to be adjusted appropriately according to the specific conditions of the product. If the blank holder force is too large, the friction between the material and the die and the blank holder ring will increase, which will make the material wall thinner or even cracked; if the blank holder force is too small, it cannot effectively prevent wrinkling. .

Second, the second problem is pulling crack, which is a problem often encountered in the stretching process. When the tensile stress on the cylinder wall exceeds the strength limit of the material, the product will crack, and the crack generally occurs at the cylinder wall slightly above the punch fillet.

The factors that affect the deep drawing crack of the product are: the tensile properties of the material, the diameter and thickness of the material, the drawing coefficient, the fillet radius of the concave and convex die, the blank holder force, the friction coefficient, etc. The radius of the rounded corner of the concave and convex die is too small and too sharp, which is easy to cause the product to crack. The general mold repair method is to find a way to increase the rounded corner to make the rounded corner smoother and brighter. Yes, especially stretching oils, are very effective. When designing the stamping die, you can enlarge the fillet as far as the customer’s product allows. Don’t make it too sharp. Some designs are not well understood. The designed drawing die cracked very badly during the die test, and wanted to exhaust the fitter. what! Repairing molds is annoying.

The use of necessary lubricants during stretching is conducive to the smooth progress of the stamping and stretching process and improves the thinning degree of the cylinder wall. But it must be noted that the lubricant can only be applied to the working surface of the die, and cannot be lubricated on the contact surface of the punch and the material, because the punch and the blank surface are a kind of favorable friction, which can prevent Material slips, cracks and thins.

What are the points of attention for the design of precision drawing molds during the processing and production of drawing parts?

First, the shortcomings of the current upward continuous stretching die.

1. The thickness of the template is not uniform. The key to the stretching die is the stripping plate, which should be thickened and the splint should be appropriately thinned.

2. The guide gap of the drawing die is large, the die and the guide post, especially the stripper plate and the guide post, the gap between the punch and the guide post is large, and the precision of the guide post is poor.

3. The choice of the spring is not very reasonable. The key to the stretching die is the blank holder, and it is necessary to ensure that the stretching cannot be wrinkled.

2. What should be paid attention to when the continuous stretching die is stretched upward?

1. Thickness of the template: Because the upper mold needs to be equipped with a spring or a nitrogen gas spring, the upper cover plate is 25mm thick as far as possible, and the upper foot is determined according to the height of the stretched product and the cover degree of the spring required.

2. Upward stretching is actually a very critical point. It is a product orientation problem, especially for products with high stretching. It is easy to deform during the stretching process. If the product is crooked, it is difficult to guide. Then every step of stretching The question of orientation is the key.

3. Clearance: stretch upward, the inner guide should be neutral as far as possible, fixed on the stripper plate, which is conducive to disassembly. Colleagues use ball guide posts, which rely on the rotation of the ball to slide, so that the guiding accuracy can be guaranteed.

4. Selection of springs: D. A group of trimming generally chooses springs that can be stripped. At the beginning, the upper springs need to bear the stretching effect, so nitrogen gas springs are required. According to the product material and the size of the material, the thickness of the material must be Choose different tonnages, try not to choose large ones, because the blanking plate needs to arrange at least 4 springs. Not only that, but also different colors of springs need to be selected according to the thickness of the material and the diameter of the material. The subsequent stretching is based on a principle that the lower spring is smaller than the upper spring, and the lower spring can be stripped.

The continuous mold production process adopted by Baifudu Electromechanical Stamping, multiple processes are completed in the same mold, and the one-time molding of the product is realized. The precision of the finished product is higher and the quality is more stable. It can produce various stainless steel tensile parts, Drawing shells, stamping deep drawing parts, metal deep drawing parts, shell drawing parts, etc., what are the points to pay attention to in the design of precision drawing molds during the processing and production of drawing parts. The relevant content is as above, I hope it can help you.

What are the design and material requirements for precision stamping parts?

Precision stamping and ordinary stamping are completely different. The minimum value of the hole diameter and hole margin of precision stamping parts is smaller than that of ordinary stamping. Therefore, when designing precision stamping parts, there are certain requirements for the design of the structure.

When designing the structure of precision stamping parts, the shape of the workpiece and the inner hole should be rounded, and sharp corners are not allowed. However, the minimum allowable corner radius value is related to the material thickness. The punching diameter, slot width and edge distance of the workpiece should not be too small. When precision stamping gears, the pitch circle tooth width of the gear should not be less than 0.6T, and the top and root of the tooth shape should be a rounded transition, not a sharp transition. The contour shape of the outer edge of precision stamping parts should be as smooth as possible, and should not change suddenly. On the surface of the workpiece, design symbols or marks, and when pressing, the cutting depth should not exceed 0.25T.

In general, the production of precision stamped workpieces is mainly based on strong blanking and fine blanking. The geometry, dimensional tolerances, geometric tolerances and shear surface quality of fine blanked workpieces are much higher than those of ordinary blanked workpieces.

The most commonly used materials in the production of precision stampings are metallic materials (including ferrous and non-ferrous metals), but sometimes non-metallic materials are also used.

Among them, ferrous metals mainly include ordinary carbon structural steel, high-quality carbon structural steel, alloy structural steel, carbon tool steel, stainless steel, electrical silicon steel, etc.; non-ferrous metals mainly include pure copper, brass, bronze, aluminum, etc.; there are many Metal materials and models. How can we choose materials, not only to ensure the quality of the workpiece, but also save materials?

When manufacturers of precision stamping parts choose stamping materials for drawing parts, they generally have the following principles:

Metal materials must meet the performance requirements of the workpiece; stamping parts work normally in machines or parts and have a certain service life.

The selected material must have good process performance; for any kind of stamping part, the selected material should be able to meet the requirements of the stamping process.

The selected material should have good economy; under the premise of meeting the performance and stamping process requirements, the material should be low in price, convenient in source and economical to reduce the cost of stamping parts.

The above are the principles that manufacturers of precision metal stamping parts should follow when choosing metal stamping materials. Hope the above content is helpful to readers.

What are the reasons for the uneven appearance of stamping parts?

1. There is no air hole on the punch.

During the stamping process, the air in the workpiece is compressed by the punch and cannot be discharged, which makes the shape of the drawn part uneven, which is often ignored by many people. The solution is to add air vents on the punch.

Second, the blank is uneven.

The rough surface is uneven, resulting in an uneven surface of the drawn part. The solution is to replace the material with a better surface quality.

Third, the material rebounds greatly.

The material has a large springback, resulting in an uneven appearance of the drawn part. The solution is to increase the annealing or shaping process.

Fourth, the gap between the punch and the die is too large.

If the gap is too large, the working surface of the mold will lose its straightening effect on the wall of the workpiece, making the shape of the workpiece uneven. Therefore, the die gap should be trimmed or replaced with new parts.

5. The negative deviation of material thickness is too large.

If the material thickness is too small, the gap between the molds will be larger, making the appearance uneven. The material needs to be replaced with a suitable thickness.

6. Improper use of stretching oil.

Select the correct stamping and drawing oil to ensure effective lubrication during the drawing process. Deep drawing processes require extreme pressure lubricants and highly effective antiwear agents. Mineral oil is generally not suitable. Stamping and drawing oil is prepared by adding oily agent, extreme pressure agent, anti-wear agent and synthetic ester. The products are widely used in calendering forming processes such as automobile panels, doors and trunks, and calendering forming processes such as carbon steel and sheet metal. It can effectively reduce the friction between the workpiece and the mold, reduce wear and tear, and the oil film is firm. It can effectively reduce the occurrence of marks, scratches, sintering welding, cracking and other phenomena. It helps the metal to slide, is conducive to forming, has no jamming, and ensures that the edge of the workpiece is smooth and free of burrs. It has good thermal stability at high temperature. Good smooth function, improve machining accuracy, protect mold, prolong mold life.

When processing metal stamping and drawing parts, if there is an uneven appearance, you may first find out the reasons from the above aspects.

What are the common materials in the production of stamping and drawing parts?

1. Stainless steel stamping and drawing parts

Stainless steel tensile parts have the characteristics of high strength, light weight, good wear resistance, and high corrosion resistance. The tensile parts of this material do not require electroplating protection. It is suitable for heat treatment and is often used in fuel systems, braking systems, exhaust systems, oxidation sensors and decorative parts in automobile manufacturing.

2. Low carbon steel stamping and drawing parts

Low carbon steel has the characteristics of excellent formability, stable forming dimensions, high strength, and light weight (see material grade for details). It is often used in various parts in automobile manufacturing, especially high-strength mechanism parts.

3. Aluminum alloy stamping and drawing parts

The characteristics of aluminum alloy tensile parts are: light weight (almost 1/3 of low carbon steel), high strength, non-magnetic, stainless rust, anodized anti-corrosion, suitable for heat treatment, etc., and are often used in bulk in automobile manufacturing and other industries. devices, energy storage devices, beverage containers and the pharmaceutical industry.

4. Copper alloy tensile parts

Copper alloy drawing parts have the characteristics of stable forming dimensions, corrosion resistance, good ductility, and easy welding. The disadvantage is that they are easy to oxidize. Due to the high price of copper alloy materials, waste needs to be reduced and recycled if necessary.

The above is related to the processing materials of stamping and drawing parts. In general, the machining methods for machining parts from different materials will vary. Material properties and processing characteristics should be considered to avoid losses. Hope the above content is helpful to readers.

What is the cause of delayed cracking in the processing of stainless steel drawing parts?

1. Delayed cracking of austenitic stainless steel. (such as 200 series, represented by 304, 300 series, etc.)

The delayed cracking of austenitic stainless steel is mainly determined by its own structure, and the degree of work hardening of austenitic stainless steel is relatively large. After stretching, in addition to the residual internal stress generated by cold working, the austenite structure also undergoes martensitic transformation at the mouth. To prevent cracking of the mouth, it is necessary to eliminate residual stress and martensitic structure, so that it can undergo phase transformation at high temperature. Austenitic stainless steel takes 304 as an example, and the annealing temperature is 1010-1050 degrees Celsius. Generally, in order to avoid the overall annealing deformation of the stretched part, only the mouth of the stretched part is annealed, and the relatively fast one is high-frequency annealing.

2. Delayed cracking of ferritic stainless steel. (For example, 400 series stainless steel represented by 430, commonly known as stainless steel)

Ferritic stainless steel does not change after stretching, and product cracking is mainly caused by residual stress. In order to ensure safety, from experience, for cylindrical deep-drawn parts, when the aspect ratio is greater than or equal to 0.8 and the diameter is greater than or equal to 300, annealing treatment is required. Of course, if cracking occurs when the aspect ratio is less than 0.8, annealing should be arranged immediately.

When using stainless steel or ferritic stainless steel materials, the use of stamping and drawing oil can reduce the breakage rate of the product and reduce the cost. The lubrication state of stamping is a mixed state of fluid lubrication and boundary lubrication. If only mineral oil is used, the strength of the oil film will not meet the requirements, and the oil film will be easily broken, which will cause metal-to-metal contact to produce sintering. The use of oily agents can make up for this deficiency. One end of the oily agent molecule contains polar groups such as carboxyl group, hydroxyl group and ester group. These polar groups can chemically or physically adsorb oily agents and form a solid lubricating film on the metal surface, thereby improving lubricating performance.

However, when the friction surface temperature rises to a certain temperature, the molecular arrangement of the oily agent adsorption film will be destroyed and the lubricating effect will be lost. At this time, the boundary lubricating film covering the surfaces of the two metals disappears, resulting in direct contact between the metals. As the direct contact area increases, the frictional energy also increases, resulting in an increase in temperature and a tendency to occur so-called sintering. In this case, the additive used to prevent direct contact between the two metal surfaces is an extreme pressure agent, even at elevated temperatures. Extreme pressure agent (EP) is a kind of boundary lubricating film that uses the high temperature generated on the friction surface to chemically change itself, generate shear force on the friction metal surface, and play an effective protective role.

Stretching of stainless steel hardware, equipment, molds and stretching oil are key factors. Otherwise, no matter how good the personnel and technology are, it is difficult for a clever woman to cook without rice, and cannot make high-quality products.

Metalworking Manufacturing Statistics: The design life of drawing equipment is about 10 years, which is caused by factors such as the equipment itself, overuse and improper maintenance. In the process of metal drawing, improper selection of drawing oil will lead to accelerated wear and tear of many equipment, and some will be paralyzed in a few years, which directly affects the operation of the whole plant and cannot maximize benefits.

What should be paid attention to when processing sheet stainless steel drawing parts?

1. Stamping characteristics of stainless steel sheet

1. High yield point, high hardness, obvious cold work hardening effect, and prone to cracks and other defects.

2. The thermal conductivity is worse than that of ordinary carbon steel, resulting in large deformation force, punching force and deep drawing force.

3. The plastic deformation is severely hardened during deep drawing, and the sheet is easy to wrinkle or fall off when stretched.

4. The deep drawing die is easy to produce adhesion tumor, which leads to serious scratches on the outer diameter of the part.

5. It is difficult to achieve the expected shape during deep drawing.

After reading the stamping characteristics of stainless steel sheet, let’s take a look at how to solve the problem of deep drawing of stainless steel sheet. The editor believes that these problems are determined by the characteristics of stainless steel itself, which are mainly affected by the following five factors:

1. Raw material properties

2. Die structure and stamping speed

3. Mold material

4. Stamping lubricant

5. Process design

And the quality of the sheet will also affect the stamping performance, so the materials we purchase should be regular and meet the standards. For hard materials, an annealing operation should be performed before stamping to increase processability.

The above is about the processing of thin-plate stainless steel tensile parts. Have you learned it? If you don’t understand anything, you can contact the webmaster of this site, and we can communicate together!

What is the reason for the wrinkling of stamping and drawing die products?

1. Factors and solutions that affect the wrinkling of stamping parts

1. The effect of stretching depth

The distribution of flow resistance along the die opening is directly related to the draw depth. On the concave and convex position, excessive stretching depth will lead to uneven distribution of deformation resistance and the formation of wrinkles. This should be avoided as much as possible.

2. Adjust the blank holder force

If wrinkles are evenly generated around the workpiece, it is judged that the holding force is insufficient, and the wrinkles can be eliminated by gradually increasing the blanking force. When stretching conical and hemispherical parts, most of the material is in air at the beginning of the stretching. Since the side wall is prone to wrinkling, it is not only necessary to increase the blank holder force, but also to increase the radial tensile stress in the plate by adding pick-up ribs and eliminate wrinkles.

3. Influence of die fillet radius

The radius of the die fillet is too large, and the blank flows into the die and passes through the die fillet, resulting in bending deformation, and the bending resistance is small. The lower the bending resistance, the easier it is to cause wrinkling. The smaller the bending deformation of the die radius, the greater the bending resistance and the smaller the possibility of wrinkling, but it is easy to cause parts to crack and pull.

Through the accumulation of practical experience in mass production, it is proved that the main reasons for the wrinkling of stamping parts are the accumulation of materials during the stretching process and the excessive speed of some materials. When formulating a practical solution, the above aspects should be considered to adjust the corresponding mold mechanism to achieve good results.

2. Measures and methods to prevent wrinkling of stamping parts

The method to prevent wrinkling is to ensure that the die can press the material during the drawing process of the metal stamping part to ensure the flow speed of the sheet. When the stamping part is stretched, the material flows too fast, which will cause wrinkles; on the other hand, the material flows too slowly, which will cause stamping cracks.

1. Use a reasonable pressing device

When the pressing device is used, the pressing device presses the deformed part of the blank, and aligns the pressing force to prevent the flange part from arching and causing wrinkles. The size of the pressing force should be appropriate. The pressing device is divided into two types: elastic pressing and rigid pressing. The elastic device is suitable for shallow drawing, and the rigid device is suitable for deep drawing.

2. Reasonable use of drawbeads

Setting drawbeads on the binder surface is an effective method to adjust and control the deformation resistance. Drawbeads can well adjust the flow of materials, so that the material flow resistance of each part during the drawing process is uniform, so that the amount of material flowing into the cavity is suitable for the needs of the workpiece, and the phenomenon of wrinkling and cracking is prevented. For curved stretched parts with complex shapes, especially those with smaller flanges, drawbeads should be set to increase the radial tensile stress of stretching to control wrinkling;

The location of the drawbead is where the radial tensile stress is smaller, that is, the location where the sheet is easy to flow. For parts with small flanges, in order to set the draw bead, some materials (process supplementary materials) can be added appropriately, and this part is removed when trimming. For drawing parts with large difference in drawing depth, draw beads should be set in the part with a small amount of feed, so as to prevent excessive material from being pulled into the mold cavity to prevent wrinkling.

3. Analysis of the causes of wrinkling of tensile parts

There are many reasons for wrinkling during stretching, the main reasons are as follows:

1. The drawing depth of the stamping part is too deep, which causes the sheet material to flow too fast during the feeding process and form wrinkles.

2. During the stretching process of the stamping part, the R angle of the die is too large, so that the punch cannot press the material during the stretching process, causing the sheet to flow too fast to form wrinkles.

3. The pressing of the stamping parts is unreasonable, the pressing ribs are too small, and the position is incorrect, which cannot effectively prevent the sheet material from flowing too fast and forming wrinkles.

Production requirements for precision metal drawing parts

What should be paid attention to when producing precision stretched parts?

1. The shape of the precision stretched product should be as simple as possible, and it should be stretched as much as possible in one processing.

2. For parts with complex appearance that need to be stretched many times, on the premise of ensuring the quality, the appearance should be allowed to have traces that may be produced during the processing.

3. Under the premise of ensuring the assembly requirements of the drawing die, the side wall of the drawing part should be allowed to have a certain slope.

4. The distance from the edge of the hole on the bottom or flange to the side wall of the precision stretch is appropriate.

2. What are the technical requirements for the processing of metal drawing parts?

In daily life, you can see many metal stretch products, such as stainless steel thermos cups, stainless steel bottle caps, stainless steel basins for kitchens, stainless steel small bowls, etc., all of which are stainless steel stretch products.

Compared with the metal stretching process, the shape of the stretched part is related to the simplicity and complexity of the stretching process. Simple shapes will be stretched into shape at a time. If the process of stretching the product is complicated, it needs to be stretched several times. Of course, under the premise of ensuring product quality, the number of deep drawing should be increased as much as possible, and the interval time of the drawing process should be extended. During the stretching process, stretch marks may appear on the surface of the product. Under the premise that the product is qualified, there is a certain slope on the side after stretching to ensure that the product size, whether it is internal or external, can achieve better stretching quality.

Another important aspect of hardware stretching is choosing the right lubricant.

The mold used for metal drawing parts is generally composed of punch, die and blank holder. The gap between the punch and the die is greater than the thickness of the sheet metal. Since the diameter of the die is smaller than the diameter of the blank, the material undergoes plastic flow during stamping and drawing. One part increases the height of the part, and the other part increases the thickness of the barrel wall. The stretching process is due to the internal interaction of the metal caused by the force of the material, resulting in internal stress between the elements in the metal. Under the action of internal stress, a strain state occurs, which causes the material to undergo plastic deformation, and is pulled into the die from time to time to become a cylindrical workpiece. The modification point of the stamping and drawing process is the transformation from a large section of the material to a cylindrical workpiece with a small section. In this process, the surface of the material and the surface of the die must be in contact to generate friction. In order to reduce the friction coefficient and reduce the extrusion force, a stretching oil with good performance must be used. The complex stretching process and lubricants also play a very important role. effect.

What are the advantages of cold stamping?

First, the advantages of cold stamping

The production process of the hardware processing factory for processing metal stamping parts is the cold stamping process. Cold stamping is based on the plastic deformation of metal. Dies on a press are used to apply downward pressure to a metal sheet or strip, separating or plastically deforming the material to achieve the desired shape, size and properties. For advanced stampings, this pressure treatment method is cold stamping.

Since the cold stamping process is a plastic deformation process, the surface of the material is not damaged, so the surface quality of the stamped parts is good, and the appearance is smooth and beautiful. This is a variety of surfaces, such as painting on the surface of stamping parts or various electroplating phosphating treatments. Provide convenience for processing, which is the main advantage of cold stamping hardware.

After the plastic sheet is deformed, the internal structure of the metal is improved, increasing the strength of the stamped part. There are two main advantages of stamping.

The third advantage of hardware cold stamping is that the dimensional accuracy of the stamped parts after processing is higher, which is opposite to the size of the die parts and has good interchangeability. Routine assembly and use requirements are met without further processing.

Whether the shape structure is a pure part or a complex hardware part, or how many sets of molds are required, it is mass-produced and can replace the high cost of molds.

Cold stamping is a processing method with high efficiency (ie high productivity) and low consumption (ie high material utilization): the cold stamping process is suitable for the production of large-scale parts, easy to realize mechanization and automation, and has high production efficiency. At the same time, cold stamping can not only achieve low-waste or no-waste production, but also make full use of leftovers without causing waste.

Under the simple stamping of the press, various parts with complex shapes that are difficult to be processed by other processing techniques can be obtained.

Since most stamping parts are made of sheet metal, their surface quality is good, which provides convenient conditions for subsequent surface treatment processes (such as electroplating, painting, etc.).

Stamping can obtain high strength, high rigidity and light weight parts with low consumption.

What are the requirements for material properties of automotive stamping parts?

First, the advantages of cold stamping

The production process of the hardware processing factory for processing metal stamping parts is the cold stamping process. Cold stamping is based on the plastic deformation of metal. Dies on a press are used to apply downward pressure to a metal sheet or strip, separating or plastically deforming the material to achieve the desired shape, size and properties. For advanced stampings, this pressure treatment method is cold stamping.

Since the cold stamping process is a plastic deformation process, the surface of the material is not damaged, so the surface quality of the stamped parts is good, and the appearance is smooth and beautiful. This is a variety of surfaces, such as painting on the surface of stamping parts or various electroplating phosphating treatments. Provide convenience for processing, which is the main advantage of cold stamping hardware.

After the plastic sheet is deformed, the internal structure of the metal is improved, increasing the strength of the stamped part. There are two main advantages of stamping.

The third advantage of hardware cold stamping is that the dimensional accuracy of the stamped parts after processing is higher, which is opposite to the size of the die parts and has good interchangeability. Routine assembly and use requirements are met without further processing.

Whether the shape structure is a pure part or a complex hardware part, or how many sets of molds are required, it is mass-produced and can replace the high cost of molds.

Cold stamping is a processing method with high efficiency (ie high productivity) and low consumption (ie high material utilization): the cold stamping process is suitable for the production of large-scale parts, easy to realize mechanization and automation, and has high production efficiency. At the same time, cold stamping can not only achieve low-waste or no-waste production, but also make full use of leftovers without causing waste.

Under the simple stamping of the press, various parts with complex shapes that are difficult to be processed by other processing techniques can be obtained.

Since most stamping parts are made of sheet metal, their surface quality is good, which provides convenient conditions for subsequent surface treatment processes (such as electroplating, painting, etc.).

Stamping can obtain high strength, high rigidity and light weight parts with low consumption.

What should be paid attention to in the processing of precision stamping parts

The five elements that must be paid attention to in the production of precision stamping parts are people, machines, materials, methods, and rings. To put it bluntly, they are people, machines, materials, methods, and environments. These five elements are very important for the processing of precision stamping parts. Next, the editor of Zhejiang Baifudu will make a specific introduction.

1. Five elements that need to be paid attention to when processing precision stamping parts

1. People: Among the five major dangers, the quality depends on the mastery of people, the characteristics of civilization, personality, attention, spirit, eyesight, and mentality. A person who has not received training will undoubtedly make a poor quality product.

2. Equipment: the accuracy, reliability and durability of mechanical equipment. If our high-speed punching machine has poor precision, will the products we produce have many problems with poor appearance and specifications? The quality of the mold will be damaged.

3. Raw materials: The quality of incoming materials and their reliability will immediately jeopardize the quality of the product. As the saying goes: if you throw in by mistake, you don’t get out.

4. Method: The accuracy, consistency and reliability of production and processing methods.

5. Natural environment: The quality of the storage environment and the office environment will damage the quality of the goods and the mentality and fighting spirit of the staff. In a messy office environment, it is impossible to make good fine stamping parts.

The above content is shared here. If you want to know more about precision stamping parts processing, please follow us, Zhejiang Balford Electromechanical Co., Ltd., located in Huzhou, Zhejiang, we are a professional consumer manufacturer of precision metal stamping, stretch forming and precision injection molding.