First, we can see the information from the situation of the waste.

First, we can see the information from the situation of the waste.

The scrap is essentially the inverse of the formed hole. That is, the same part in the opposite position. By carefully inspecting the scrap, you can infer whether the upper and lower die gaps are accurate. If the gap is too large, the scrap will exhibit rough, undulating fracture surfaces and a narrow bright band area. The larger the gap, the greater the angle the fracture surface makes with the bright band area. If the gap is too small, the scrap will exhibit a small angled fracture surface and a wide bright band area.

Excessive clearance creates holes with large curls and edge tearing, leaving the cut face slightly protruding with a thin edge. A gap that is too small results in a slight hemming of the tape and a large angular tear, resulting in the cut plane being more or less perpendicular to the surface of the material.

An ideal scrap should have a reasonable collapse angle and a uniform bright band. This keeps the punching force low and creates a clean round hole with very few burrs. From this point of view, increasing the die life by increasing the clearance is at the expense of finished hole quality.

Second, the choice of mold clearance

The clearance of the die is related to the type and thickness of the material being punched. Unreasonable clearance can cause the following problems:

(1) If the gap is too large, the burr of the punched workpiece is relatively large, and the quality of the punched product is poor. If the clearance is too small, although the quality of the punched product is good, the wear of the die is quite serious, which greatly reduces the service life of the die and easily causes the punch to break.

(2) If the gap is too large or too small, it is easy to cause adhesion on the punch material, which will cause the material to be tapered during punching. If the gap is too small, it is easy to form a vacuum between the bottom surface of the punch and the sheet, and the waste will bounce back.

(3) Reasonable clearance can prolong the life of the mold, the discharge effect is good, the burrs and flanging are reduced, the plate is kept clean, the hole diameter is consistent and the plate will not be scratched, the number of sharpening is reduced, the plate is kept straight, and the punching positioning is accurate.

3. How to improve the service life of the mold

For users, improving the service life of the mold can greatly reduce the stamping cost. The reasons that affect the service life of the mold are as follows:

1. The type and thickness of the material.

2. Whether to choose a reasonable die gap.

3. The internal structure of the mold.

4. Whether the material is well lubricated during stamping.

5. Whether the mold has undergone special surface treatment.

6. Such as titanium plating, titanium carbonitride.

7. The neutrality of the upper and lower turrets.

8. Adjust the rational use of gaskets.

9. Whether the oblique edge mold is used properly.

10. Whether the die base of the machine tool has been worn.

Fourth, the problems that should be paid attention to when punching special size holes

(1) Please use a special punch for punching in the range of φ0.8-φ1.6 with the minimum hole diameter.

(2) When punching a thick plate, use a die one size larger than the hole diameter. Note: At this time, if a normal size die is used, the punch thread will be damaged.

(3) For the cutting edge of the punch, the ratio of the minimum width to the length should generally not be less than 1:10.

(4) The relationship between the minimum size of the punch edge part and the plate thickness. It is recommended that the smaller size of the punch edge part be 2 times the thickness of the plate.

5. Sharpening of the mold

1. The importance of mold sharpening

Regular sharpening of the die is the guarantee of consistent punching quality. Regular sharpening of the mold can not only improve the service life of the mold but also improve the service life of the machine. It is necessary to master the correct sharpening timing.

2. The specific characteristics of the mold that needs to be sharpened

For die sharpening, there is no strict number of blows to determine if sharpening is required. mainly depends on

The sharpness of the cutting edge. It is mainly determined by the following three factors:

(1) Check the fillet of the cutting edge. If the fillet radius reaches R0.1 mm (the maximum R value must not exceed 0.25 mm), it needs to be sharpened.

(2) Check the punching quality, is there a large burr?

(3) Judge whether sharpening is required by the noise of machine stamping. If the noise is abnormal when the same pair of die is punched, it means that the punch is dull and needs to be sharpened.

Note: If the edge of the cutting edge becomes rounded or the rear of the cutting edge is rough, sharpening should also be considered.

3. The method of sharpening

There are many ways to sharpen the mold, which can be realized by a special sharpening machine or a surface grinder. The frequency of punch and die sharpening is generally 4:1. Please adjust the height of the die after sharpening.

(1) Harm of incorrect sharpening method: Incorrect sharpening will aggravate the rapid destruction of the die edge, resulting in a greatly reduced number of blows per sharpening.

(2) The benefits of the correct sharpening method: regularly sharpening the mold, the quality and precision of the punching can be kept stable. The cutting edge of the mold is damaged slowly and has a longer life.

4. Sharpening rules

The following factors should be considered when sharpening the mold:

(1) The fillet of the cutting edge depends on the sharpness of the cutting edge in the case of R0.1-0.25 mm.

(2) The surface of the grinding wheel should be cleaned.

(3) It is recommended to use a loose, coarse-grained, soft grinding wheel. Such as WA46KV

(4) The amount of grinding each time (the amount of knife cutting) should not exceed 0.013 mm. Excessive grinding will cause the surface of the mold to overheat, which is equivalent to annealing treatment, and the mold becomes soft, which greatly reduces the life of the mold.

(5) Sufficient coolant must be added during sharpening.

(6) When grinding, the punch and the lower die should be fixed smoothly, and a special fixture should be used.

(7) The sharpening amount of the mold is certain. If this value is reached, the punch will be scrapped. If you continue to use it, it is easy to cause damage to the mold and the machine, which is not worth the loss.

(8) After sharpening, the edge should be treated with whetstone to remove excessively sharp ridges.

(9) After sharpening, it should be cleaned, demagnetized and oiled.

Note: The amount of die sharpening mainly depends on the thickness of the punched sheet.

Six, the punch should pay attention before using

1. Storage

(1) Wipe the inside and outside of the upper die sleeve with a clean rag.

(2) Be careful not to scratch or dent the surface during storage.

(3) Oiled to prevent rust.

2. Preparation before use

(1) Thoroughly clean the upper die sleeve before use.

(2) Check the surface for scratches and dents. If so, remove with whetstone.

(3) Oiling inside and out.

3. Matters needing attention when installing the punch on the upper die sleeve

(1) Clean the punch and oil its shank.

(2) Insert the punch into the bottom of the upper die sleeve on the large-station die without using force. Nylon hammers cannot be used. During installation, the punch cannot be fixed by tightening the bolts on the upper die sleeve, and the bolts can only be tightened after the punch is positioned correctly. Zhengquan Technology WeChat content is really good, it is worth paying attention to!

4. Install the upper die combination into the turret

If you want to prolong the service life of the mold, the gap between the outer diameter of the upper die sleeve and the turret hole should be as small as possible. So please perform the following procedures carefully.

(1) Clean and oil the keyway and inner diameter of the turret hole.

(2) Adjust the keyway of the upper die guide sleeve to match the key of the turret hole.

(3) Insert the upper die sleeve straight into the tower hole, being careful not to have any inclination. The upper die guide should slide under its own weight into the turret hole.

(4) If the upper die sleeve is inclined to one side, use a soft material tool such as a nylon hammer to tap it gently and repeatedly until the upper die guide sleeve slides into the correct position by its own weight.

Note: Do not use force on the outer diameter of the upper die guide sleeve, but only on the top of the punch. Do not tap the top of the upper die sleeve, so as not to damage the turret hole and shorten the service life of individual stations.

Seven, mold maintenance

If the punch is caught by the material and cannot be taken out, please check the items listed below.

1. Re-sharpening of punch and lower die. A mold with a sharp edge can process a beautiful cut surface. If the edge is blunt, additional punching force is required, and the workpiece has a rough section, which produces great resistance, causing the punch to be bitten by the material.

2. The gap of the mold. If the gap of the die is not properly selected relative to the thickness of the plate, the punch needs a large demoulding force when it is separated from the material. If this is the reason the punch is bitten by the material, please replace the lower die with a reasonable clearance. Zhengquan Technology WeChat content is really good, worthy of attention!!

3. The state of the processed material. When the material is dirty or dirty, the dirt adheres to the die and the punch is caught by the material and cannot be processed.

4. Deformed materials. The warped material clamps the punch after the hole is punched, causing the punch to bite. For warped materials, please flatten them before processing.

5. Excessive use of springs. will fatigue the spring. Always pay attention to check the performance of the spring.

Eight, oiling

The amount of oil and the number of oil injections depend on the conditions of the material being processed. For cold-rolled steel plates, corrosion-resistant steel plates and other rust-free and non-scaling materials, oil should be injected into the mold. The oil injection points are the guide bush, the oil injection port, the contact surface between the cutter body and the guide bush, and the lower die. Use light motor oil.

For materials with rust and scale, the rust powder will be sucked between the punch and the guide sleeve during processing, resulting in dirt, so that the punch cannot slide freely in the guide sleeve. In this case, if oil is applied, it will make the rust easier Therefore, when flushing this material, on the contrary, wipe the oil clean, decompose it once a month, use gasoline (diesel) oil to remove the dirt on the punch and the lower die, and wipe it before reassembly. This ensures that the mold has good lubricating properties.

Nine, the problems and solutions that often occur during the use of the mold

Problem 1. The plate comes out of the clamping jaw

Reason: incomplete unloading of the mold

Solution:

1. Use a taper punch

2. Apply lubricating fluid on the plate

3. Adopt heavy duty mould

Problem 2, the mold is seriously worn

Reason: unreasonable die gap (small)

Solution: increase the mold gap

Reason: The upper and lower die bases are not aligned

Solution:

1. Work station adjustment, centering of upper and lower molds

2. Turret level adjustment

Reason: The worn mold guide components and the inserts of the turret were not replaced in time

Solution: replace

Reason: Punch overheating

Solution:

1. Add lubricating fluid to the sheet

2. Ensure lubrication between punch and lower die

3. Use multiple sets of molds of the same size in the same program

Reason: improper sharpening method, resulting in annealing of the mold, resulting in increased wear

Solution:

1. Use soft abrasive grinding wheel

2. Clean the grinding wheel frequently

3. Small amount of knife

4. Sufficient coolant

Reason: small step

Solution:

1. Increase the step distance

2. Adopt bridge nibbling

Problem 3. Punch material and punch sticking

Reason: unreasonable die gap (small)

Solution: increase the mold gap

Reason: Passivation of punch edge

Solution: sharpen in time

Reason: poor lubrication

Solution: Improve lubrication conditions

Problem 4. Scrap rebound

Reason: die problem

Solution:

1. Using bulletproof material to lower the mold

2. For small diameter holes, the clearance is reduced by 10%

3. When the diameter is greater than 50.00 mm, the gap is enlarged

4. Increase scratches on the edge side of the die

Reason: punch

Solution:

1. Increase the depth of the mold

2. Install the unloading polyurethane ejector bar

3. Adopt oblique cutting edge

Problem 5. Difficulty in unloading

Reason: unreasonable die gap (small)

Solution: increase the mold gap

Reason: punch wear

Solution: sharpen in time

Cause: Spring fatigue

Solution: replace the spring

Reason: Punch sticking

Solution: Remove the sticking

Question six, rush

What is the structure of metal stamping die?

1. Structure of metal stamping die

The structure of metal stamping die can generally be divided into upper die and lower die. The upper die is composed of a die handle (punch handle), a guide sleeve, a punch, a backing plate, a fixing plate, a screw, a pin, an upper die seat (upper support), and a stripping plate. The lower die is generally composed of a lower die base, a guide plate (side guide plate), a concave die, a baffle plate, a material bearing plate, a guide post, a screw and a pin.

1. The above is an ordinary blanking die, the product is a rectangle with three small round holes punched in the middle;

2. The blanking and punching composite punch is a cuboid, and its function is to blank and remove the shape of the product from the material. The blanking and punching compound punch is also surrounded by knife edges, which are equivalent to punches, so these four sides cannot be chamfered. There are three small round holes in the middle of the blanking and punching compound punch. These three small round holes belong to the knife edge. That is, punch out the three round holes in the middle of the product.

3. There is a square hole in the middle of the concave template, which belongs to the knife edge. The blanking punching compound punch is used as a punch to punch out the shape of the product; The inner unloading plate, marked as “unloading block” in the picture, actually means the same thing. The function of the unloading block is to push the product out of the concave formwork; After the material is pressed, punch the three small round holes in the middle.

4. The “top-type punch” marked in the picture is actually a punch, which punches out the three small round holes on the intermediate product with the three circular knife edges on the blanking punching compound punch.

5. The function of the “fixed key” on the bottom plate of the lower die is to fix the blanking punching composite punch, so as to prevent it from jumping out of the die with the upward movement of the die, resulting in an accident.

6. The “discharge plate” marked on the lower die is commonly known as external release. Its function is to release the punched waste from the blanking punching compound punch, so as to prevent the waste from being stuck on the blanking punching compound punch.

2. What are the categories of metal stamping dies?

Stamping die parts are usually divided into two categories, one is process parts, which directly participate in the completion of the process and have direct contact with the blank. Contact only plays a role in guaranteeing the completion of the process of the mold, or perfecting the function of the mold, including guiding parts, fastening parts, standard parts and other parts. It should be pointed out that not all dies have the above-mentioned six parts, especially single-process dies, but working parts and necessary fixed parts are indispensable.

What are the advantages of precision metal stamping parts processing?

1. What is precision metal stamping?

Precision metal stamping is a high-volume metalworking process that uses stamping tools to press material into the desired shape to create sheet metal parts. This is done according to a pattern where each part is removed from the motherboard after stamping.

Precision metal stamping enables manufacturers to create parts that require undercuts, multiple features, or frangible walls for assembly. It uses high-pressure equipment to press the metal plate into the mold, so the shape of the product has geometric accuracy and good surface finish.

Second, the advantages of precision metal stamping

Precision metal stamping offers manufacturers and end users a variety of advantages. These include:

1. Mass production

Precision metal stamping can make thousands to millions of parts in a single run. This is more productive than other metalworking processes such as CNC machining, fabrication or welding.

This process is ideal for high volume manufacturing, where hardware parts are manufactured in large volumes.

2. Uniformity

Precision metal stamping is versatile, the same tooling can be used to produce a variety of components, and requires little additional setup or adjustment between production runs.

Therefore, precision metal stamping has higher uniformity compared to other industrial processes. Since all products are stamped from sheet, they have the same wall thickness and nearly the same surface finish, making post-production assembly and quality control inspections easier.

Precision metal stamping also supports mass customization of final products through automated variable design to quickly meet unique customer requirements.

3. Quality

Precision metal stamping is a versatile process capable of producing a range of parts with varying surface finishes and tolerances.

It also produces parts with thin walls, deep draws and undercuts that would otherwise be challenging to produce using other processes such as CNC machining or fabrication.

This makes precision metal stamping an excellent choice for aerospace, medical implants, automotive, lighting and consumer electronics product development where precise shapes and thin walls are required.

Precision metal stamping is one of the few technologies capable of producing the specific thin-wall geometries required for demanding electronic packaging applications due to its ability to create deep-drawn features.

4. Ease of use

Engineers and designers find precision metal stamping easy to use because it can replace complex shapes with minimal tooling.

This capability provides customers with greater design flexibility and opens the door to conceptual exploration early in product development.

It also helps them reduce costs by minimizing material waste, as fewer mold changes are required with each new part design iteration.

Using precision metal stamping makes it easier to manufacture precisely designed parts because they require less machining time for secondary operations throughout the production process. This results in a more efficient workflow, especially at high volumes.

5. Minimize material waste

Precision metal stamping is an economical manufacturing process because it uses the minimum amount of material needed to make the part.

This feature allows manufacturers to manufacture thin-walled products without the need for complex secondary operations, such as CNC machining, which can be time-consuming and expensive.

6. Cost-effectiveness

Compared to large die casting machines for mass production, precision metal stamping has lower start-up costs. Therefore, it is beneficial when the production demand is not large but the volume is still high.

It also provides a high degree of flexibility, with design options available to manufacturers for custom-made items that cannot be produced any other way. This means they can earn higher profits without much initial investment.

7. Least secondary operations

For precision metal stamping, secondary operations, such as cutting threads after production, are usually not required. The process simultaneously creates accurately shaped features without any errors, such as pre-drilling, countersinking, or cutting threads. Secondary machining often adds cost and time-to-market, but hand-finishing is minimal after stamping, again saving money and time.

3. Precautions when using precision metal stamping technology

1. Surface quality

The surface quality of a stamped part depends on the metal used, its hardness, thickness and whether it is heat treated after stamping. Softer materials are more prone to scratching during the stamping process, while thicker metals are less prone because they are more resistant to pressure from the tool. Heat treatment helps improve the grain structure of the metal, making it harder and more resistant to wear without compromising the strength of the material.

2. Undercut

Undercuts can cause difficulties during stamping because they make it difficult for the tool to fully penetrate the sheet metal.

One way to get around this is to use a progressive die instead of one big die to cut out the shape of all the parts at once. Multiple dies perform small cuts until all part features are achieved. Progressive punching also reduces the force required to release the undercut, but it also limits production speed and can lead to irregular shapes that require secondary operations to clean up.

3. Tolerance and Accuracy

Tolerance refers to the amount of variation allowed in dimensions in the part design, while accuracy refers to how close the final measurement is to the expected dimensions.

Precision metal stamping can achieve precise dimensions and tight tolerances because, unlike other manufacturing processes, it uses controlled forces to produce parts.

Parts produced using this process are closer to specification than parts made using alternative methods such as CNC machining or welding.

4. Material strength and tool wear

To keep costs low, manufacturers often use softer, cheaper metals to make tools. However, using less robust tooling results in a compromise in material strength that can adversely affect design and quality, especially when the product requires thin-walled geometries. Such tools can place excessive compressive stress on components.

Stress from the tool is a major cause of material deformation, so this trade-off must be considered when designing metal stampings.

5. Product complexity and cost

The complexity of a part’s design determines how many tools are required to manufacture all its features. However, manufacturers may address this cost by performing secondary operations on specific components in the same production run, rather than making unique tooling for complex shapes or geometries such as undercuts.

This allows manufacturers to produce multi-component products in multiple materials at once without increasing costs.

4. Summary

Precision metal stamping is used in a variety of industries to produce metal parts with complex geometries and other features that are too costly or impossible to manufacture with alternative manufacturing methods such as die casting and machining.

While manufacturers need to consider budget, machine capacity, tool quality, and other factors when choosing the right process for their business, precision metal stamping is known for its accuracy.

How to solve the tensile cracking in the processing of stainless steel stamping parts?

When the stamping part of stainless steel plate is cracked, there are four kinds of situations that often occur. There are four kinds of such situations. They occur immediately after the tensile deformation and exit from the stamping part. After the drawing deformation, shock or vibration occurs. Will appear for a while or in use. The cause of lateral cracks or point cracks in the sidewall of stainless steel stamping parts may be caused by material inclusions, ferrite and other intergranular defects, or it may be the deep drawing process and deep drawing cracks that occur during the processing of stainless steel stamping parts and other reasons.

The transverse cracks or point cracks on the side walls of stainless steel deep-drawing parts are mainly caused by inclusions or ferrite in the matrix. In the production process of stainless steel, the following two points should be paid attention to:

(1) Improve the purity of the material and reduce the inclusion content in the matrix of the stainless steel material.

(2) Improve the component design and hot rolling, cold rolling annealing process, and reduce the ferrite content of the stainless steel matrix.

However, in the production process of stainless steel materials, these two kinds of processing defects will inevitably occur, so in the process of stamping products such as thermos cups, pressure cookers, and inner pots, appropriate technological measures can also be taken to reduce or avoid inclusions or Crack phenomenon caused by ferrite defects.

(1) Change the forming method from thinning and deep drawing to equal thickness drawing.

(2) Increase the number of stretching passes, increase the fillet radius of the die, and reduce the difficulty of material deformation.

(3) Appropriately increase the viscosity of the drawing oil to promote uniform deformation of the material and avoid excessive stress concentration.

The above is the content about the cracking of stainless steel stamping and drawing parts. It should be noted that in the forming process of stainless steel drawing parts, the die should be used first, and then the cooling of the heat generated during the drawing process should be controlled, and the drawing process should be controlled. The cooling of the heat generated during the stretching process, the upper and lower molds can be cooled if conditions permit. I hope the above can be helpful to readers.

What is the reason for the wrinkling and cracking of automobile covering tensile parts?

The direct reason for the cracking of the workpiece is that the tensile deformation resistance is higher than the actual effective tensile strength of the material at the simple wall crack. The appropriate adjustment method to completely eliminate the breakage of the puller is as follows:

(1) Adjust the pressing material pressure and reduce the pressure.

(2) Adjust the stretching gap to make the gap larger and more uniform.

(3) Adjust the radius of the mold fillet. If the radius of the mold fillet is too small, the parts are easy to crack. Increasing the die fillet radius can reduce the degree of pull cracking.

(4) Adjust the radius of the die fillet.

(5), adjust the relative position of punch and die.

(6) The size of the blank is too large or the shape is incorrect, and the quality and lubrication of the plate may also cause the parts to crack. The size or shape of the blank should be changed, and the stamping process should be adjusted.

There are many reasons why parts can crack. When adjusting, carefully check the state and position of the crack, determine the stroke position of the crack, infer the cause of the crack according to the specific situation, and then work out a specific solution to the crack.

Some experience in solving trial wrinkling and cracking.

During the initial deep drawing of the drawing die, the drawn parts are generally wrinkled and cracked. At this time, it is necessary to carefully observe the condition of the pressing surface and analyze the various causes of wrinkles. If there are indentations on the pressing surface and cracks at the radius of the concave die, it means that feeding is difficult; if the pressing surface is corrugated, it is easy to feed. Later, due to the generation of material corrugations, it is difficult to flow, resulting in wrinkling and cracking, that is, the material is difficult to flow during the stretching process, which will cause wrinkling and cracking during the stretching process, so different situations should be solved by different methods.

Feeding difficulties are usually caused by excessive binder resistance. If the surface roughness of the binder surface and the die fillet is too high, or there is recoil forming and local stretching is too large, it is necessary to adjust the outer slider, reduce the blank holder force, and appropriately increase the die fillet. Reduce the surface convexity and appropriately increase the lacing clearance. If the local tensile deformation is too large and inversion occurs, it should be solved by adding process gaps or process holes.

The feeding is easy, mainly because the feeding resistance is too small, the contact of the pressing surface is poor, or the design process performance of the drawing part is poor. If it is a binder surface problem, the binder surface needs to be ground to ensure adequate contact. In addition, the outer slider can be adjusted to increase the blank holder force or increase the blank holder area. If the process performance of the stretched part is not good, it is necessary to redesign the stretched part to make it a qualified product.

The above only discusses how to prevent or solve the wrinkling problem of the cover from the aspects of technology, drawing die design and adjustment. There are many reasons for the wrinkling and cracking of the cover. But as long as the phenomenon is carefully studied and classified, different situations can be solved in different ways, resulting in a coating of good surface quality. Hope the above content can be helpful to readers.

How to choose raw materials for automobile stamping parts?

A large number of cold stamping processes are used in the processing and production of automobile stamping parts, which meets the requirements of the automobile stamping parts processing industry for various varieties and production. Medium-heavy vehicles, large-sized surface cage parts, such as body outer panels, and some load-bearing and support parts, such as frame, carriage and other auto parts, are processed by automotive stamping parts. The cold stamping parts are made of steel plates and steel belt fasteners, accounting for 72.6% of the total installed steel volume. The relationship between cold stamping die materials and automotive stamping parts processing and production is very close. The quality of the product not only determines the performance of the product, but also directly affects the process planning of the automotive stamping parts processing process, and affects the quality, aging, service life and production structure of the product. Therefore, the selection of suitable raw materials is one of the important factors, and it is also a very difficult and complicated task.

Generally, the car stamping parts we use are all directed to beautiful, applicable and economical. However, when weighing the quality of stamping parts, we should pay more attention to the number of processes of stamping parts. In addition, reducing the number of processes and simplifying the operation process in the stamping process is also a difficult problem. Then, when commenting on the quality problems of car parts, it can also be identified by the layout of stamping parts.

Of course, a small number of car stamping parts use a little standard when judging the quality. In the process of application, it is not easy to describe with pen and ink, but there is a little standard or existence for judging the quality.

Common defects in car stamping materials include burrs, wood surface warpage, and dimensional deviations.

Automobile connecting rod stamping parts are generally difficult to avoid poor burrs, but if the processability of the formed products is improved and the stamping conditions are improved, the burrs can be reduced.

This is a glitch, a little more important:

1.1 Clearance

The gap of the stamping parts is too large, too small or uneven, which will cause burrs. The main reasons for gaps that are too large, too small, or uneven are as follows:

– Mould manufacturing error – The processing of mould parts does not conform to the drawings, the parallelism of the bottom plate is poor, etc.

Assembly error – large guide rail clearance, poor concave-convex assembly, etc.

Poor pressure accuracy – For example, the clearance of the press guide rail is too large, the parallelism between the bottom of the rocker plate of the slider and the surface of the table is poor, probably because the sliding distance of the slider and the verticality of the table of the press are poor, and the rigidity of the table is poor.

d Installation error – For example, the upper and lower bottom surfaces of the mold are not wiped clean during installation, the fastening technique of the upper mold of the large mold is wrong, or the center of the upper and lower molds (especially the non-guided mold) may be installed, and the movement is unilaterally skewed.

The layout of the e-die is divided into the lack of rigidity of the die head and one-sided, and the unbalanced force of automobile stamping parts.

The curvature of the steel hoist is large – the steel plate is not satisfied.

1.2 The knife edge is slow.

Slow sharpening or biting can cause burrs. The influencing factors of edge passivation are:

Die convex, concave and convex materials and their surface treatment conditions are not good, poor wear resistance.

Poor typography, poor rigidity, and crunch.

It cannot be lubricated in time during operation and wears quickly.

d The geodetic front cannot be ground immediately.

The above is related to the processing of automobile stamping parts. There are many kinds of automobile stamping parts, so the selection of stamping parts also has strange specifications. And there must be a good treatment method for the common defects in the processing of automobile stamping parts. I hope the above can be helpful to readers.

Assembly principles and debugging points of metal stamping parts

The key to die assembly of metal stamping parts is to ensure that the upper and lower die bases are raised, the concave die and related parts can work normally in the corresponding positions of the clamping die, and the workpieces that meet the product requirements are stamped out. , It should be mentioned that various components used for assembly need to meet the assembly process requirements proposed by various parts.

For example: for the fixing plate of multiple punches, the relative position dimensional accuracy and step distance accuracy between each type of hole must meet the requirements of the concave die and the discharge plate. The bolts and pins on the backing plate pass through the holes, which can be marked, Quenching, upper and lower surfaces should be strictly polished and flat. The overall concave die installed on the upper and lower die bases should not only meet the graphic requirements, but also process bolt holes and pin holes. After heat treatment and finishing to be put into assembly. Need to connect the fixed mold base. When assembling the guide plate, the screw holes and pin holes on the guide plate should be drilled through the corresponding holes on the die. With hinges; the mold type and structural characteristics of hardware stamping parts Although they are different, the assembly methods and installation sequences used are also different, but the assembly principles should be followed.

When assembling a die for metal stamping parts, first select the assembly base as the assembly benchmark for the metal stamping die, and then gradually assemble other die parts according to the benchmark components; the selection of the benchmark components depends on the structural characteristics of the metal stamping die; guide plate mold The frame should also be used as the guide plate of the unloading plate as the assembly reference part; the metal punching die guided by the guide column generally uses the concave die as the assembly reference part, and the blanking punching compound die selects the ejector plate as the assembly reference part, and the push plate is used as the assembly reference part. The premise is that the output center point is opposite to the center of the tie rod.

After selecting the reference parts, the parts of the metal stamping die are first assembled into assemblies according to their independent connection relationships, and then the base parts are used as the assembly benchmark to complete the assembly of the metal stamping parts.

What are the key points for debugging of metal stamping molds in the processing workshop?

1. Close debugging of metal stamping die. The die and the die should be matched to ensure their proper clamping height and opening height.

2. Debugging of the guide device. The guide column and guide sleeve must have good matching accuracy to ensure the stable and reliable movement of the metal stamping die.

3. Debugging of convex and concave die edges and gaps. The blade is sharp and the gap should be even.

4. Debug positioning equipment. The location should be precise and reliable.

5. Uninstall and uninstall the debugging of the device. The discharge and discharge should be smooth, and there will be no jamming.

The above is the relevant content about the assembly and debugging of the metal stamping part mold, the metal stamping part mold is a one-time production. Some parts that constitute the mold entity are processed separately according to the dimensions and tolerances marked on the drawings during the manufacturing process. Such parts are usually directly assembled. Some parts can only be dimensioned according to the drawings during the manufacturing process, and the relevant dimensions can be coordinated. . I hope the above can be helpful to readers.

What performance should metal stamping die processing have?

Metal stamping die processing should have the following properties:

Forgeability: low hot forging deformation resistance, good plasticity, wide temperature range, low tendency for forging cracking, cold cracking and network carbide separation.

Cutting technology: large cutting amount, small tool loss, and low surface roughness.

Processability: The spheroidizing annealing temperature range is wide, the annealing hardness is low, the disturbance generated is small, and the spheroidization rate is high.

Hardening: case hardening, case hardening, uniform surface hardness.

Hardening: After hardening, a deeper hardened layer can be obtained, and a mild quenching medium can be selected for hardening.

Abrasiveness: The relative loss of the grinding wheel is small, the limit of grinding without ablation is large, and it is not sensitive to the quality of the grinding wheel and cooling conditions, and the grinding fine blanking die will not be worn and cracked.

Oxidation method. Sensitivity to decarburization: At high temperature, the antioxidant absorber is good, the decarburization rate is slow, it is not sensitive to the heating medium, and pitting is easy to occur.

Casting mold manufacturing to go through cutting, heat treatment and other processes. The craftsmanship is difficult, the requirements for production materials are high, and good processing performance is required to ensure that the manufacturing of Seiko metal stamping dies has no process defects and stable quality.

Precautions for the selection of metal stamping parts:

1. There are many kinds of steel plate specifications, whether it is a fixed plate or a coil plate, the sales price is also different for the same material, thick material and different coil width. Therefore, in order to reduce costs, it is necessary to work hard on the setting of the purchase volume, and on the premise of ensuring the utilization rate of materials, try to choose a roll width range that does not increase the price. If you try to choose the appropriate size for the fixed-length plate, it is not necessary to carry out secondary cutting after cutting from the steel mill, so as to reduce the shearing cost; work efficiency.

2. The thickness of the plate has deviation requirements, generally within the allowable range of deviation, first select the plate with smaller deviation.

3. Determining the shape and size of the stamping parts display board is the premise of analyzing the deformation degree of the stamping parts, the design process and the preparation of the process specification. If the shape of the sheet is appropriate, not only the uneven distribution of the sheet along the sheet can be significantly improved, but also the forming can be improved, the height of the lug can be reduced, and the trimming allowance can be reduced. In addition, for some parts that are directly formed, if the shape and size of the sheet metal can be given, the number of mold adjustments can be reduced, thereby shortening the production cycle and improving productivity.

4. When selecting materials for product design, avoid excessive product performance due to the selection of high-grade materials. At the same time, under the premise of meeting product and process requirements, try to choose the materials and thick materials used in the existing mass-produced models to form a material platform to facilitate subsequent procurement and inventory management. For example, the main performance requirement of general cold-rolled sheet is tensile performance, so in the case of consistent product quality, try to choose low-specification materials. And in the selection of material thickness, in addition to considering the strength and weight after molding, we should also pay attention to the flatness of the material thickness. Due to the special thickness of raw materials, it is difficult and expensive for suppliers to supply.

The above is related to the selection of metal stamping dies and materials. For the processing of metal stamping parts, the shape of the stamping parts should be simple and the structure should be reasonable. In order to make the structure of the abrasive tool simple, our purpose is to use fewer and simple stamping parts for processing, which is beneficial to the stamping operation, not only can improve labor productivity, but also facilitate the organization and production of stamping parts, which is conducive to mechanized and automated production. Hope the above content can be helpful to readers.

What is the reason for the explosion of the metal stamping die?

First, choose the press

In order to prolong the service life of the metal blanking die, a high-quality punch should be selected. The average regrind life of the open press is 10,000-30,000 times, while the die life of the new precision press can reach 60,000-12,000 times. Especially for dies with small or no gaps, cemented carbide dies and precision stamping dies, presses with high precision and good rigidity should be selected, otherwise the service life of the die will be reduced, and the die will be damaged in severe cases.

2. Reasons for mold design

Usually, if the structure is unreasonable, the strength is insufficient, the distance between the knife edges is too close, the number of template blocks is insufficient, or there are no feet, etc., the mold will have a great risk of bursting. The mold design mainly includes the following:

1. Nesting and lap joint: The reciprocating feeding method often leads to damage to the mold, and the lap value is too small, which aggravates the wear of the mold. Therefore, choosing a reasonable layout method and overlapping boundary values ​​can prolong the life of the mold and avoid the situation of mold explosion.

2. Guide rail accuracy: The guide rail has high precision and reliability, which can reduce the wear of the guide rail and avoid the gnawing of the convex and concave die. Especially suitable for no gap, small gap blanking, compound, multi-station progressive die. In addition, according to the characteristics of the processing technology and the accuracy of the parts, choosing the correct form of guide and the accuracy of the guide mechanism is the key to improving the service life of the mold.

Third, the reason for the processing technology

The experimental results show that the thermal processing quality of the mold has an important influence on its performance and life. According to the analysis and statistics of failure causes, more than 40% of mold failure accidents are caused by improper heat treatment. In the manufacture of blanking die, improper quenching and tempering process will cause deformation of the finished product and eventually cause the die to burst.

1. Preheating heat treatment: According to different mold materials and requirements, operators should adopt preparatory heat treatment methods such as annealing, normalizing, and quenching and tempering to eliminate structural defects in forgings and improve the level of processing technology. In addition, proper preheating of the mold raw materials can make the carbide distribution more uniform, which is beneficial to ensure the quality of quenching and tempering, and prolong the service life of the mold.

2. Quenching and tempering: This is an important part of mold heat treatment. If the quenching temperature is too high, the brittleness of the mold will be strengthened, which will cause the product to be easily deformed and fractured during the cooling process, which will seriously affect the service life of the mold. Quenching and heating must be carried out in strict accordance with the heat treatment process regulations, with particular attention to oxidation, decarburization and other phenomena. If conditions permit, vacuum heat treatment can be used. In addition, tempering should be carried out in time after quenching, and different tempering processes should be selected according to technical requirements.

4. Surface strengthening treatment

In order to improve the performance and life of stamping dies, the surface strengthening treatment of die workpieces is more and more widely used. Common surface strengthening methods are liquid carbonitriding, ion nitriding, boronizing, vanadium and spark strengthening, chemical vapor deposition (CVD), physical vapor deposition (PVD), carbide immersion in a salt bath (TD) In addition, surface strengthening treatments such as high-frequency quenching, hydraulic pressure, and shot peening can generate compressive stress on the surface of the mold workpiece, improve its fatigue strength, and help prolong the service life of the mold.

The above is the content related to metal stamping dies. The selection of stamping equipment is directly related to a series of important issues such as equipment safety, production efficiency, stamping quality, punching die life and production costs. Therefore, careful selection is required. Hope the above content can be helpful to readers.

Stamping dies, protective measures for stamping operations

The main reason for the formation of the mold is: the mold is misguided and skewed. Otherwise, it will cause mold damage and mold deformation, such as mold base, template hardness, template thickness planning is too small, easy to be affected by external force collision deformation; mold orientation is not correct, the upper and lower mold positioning error is out of tolerance. At this time, the strength of the punch should be increased to strengthen the guidance of the stripper. It may also be that the precision of the die is too low, resulting in a dryness of the die that is not proportional to the strength of the die. The orientation of the mold is too close, causing the lateral force of the mold to be unbalanced. When stamping, once the mold is insensitive or even stuck, stop production immediately, find out the cause of the stuck mold, and eliminate the problem.

The cost of mold production is high, and the cost of ordinary molds accounts for 1/4-1/5 of the cost of stamping molds. The cost of a trim is more than 70% of the original cost of the mold, and the life of the mold may be approaching. If the mold repair process is too complicated, the mold repair cost is too high, the difficulty is too high, and the maintenance cycle is too long, it will seriously affect the normal production of stamping parts.

Under normal circumstances, after the mold is damaged, there will be a multiple-choice question to repair and invalidate it. However, in this way, the mold can be repaired in time, effectively avoiding damage to the mold, and can greatly reduce the cost of the mold for stamping production. After the die sleeve is seriously damaged, sometimes the punch and the die are damaged together. The reason is that, in addition to the difficulty of mold manufacturing, the cost is too high. Unnatural wear of the blanking die fails, if not for damage to the connecting parts.

Under normal circumstances, the main failure mode of the die is excessive wear, which requires the manufacture and use of the die again. Therefore, timely repair and prevention of molds can greatly reduce the cost of molds for stamping parts.

In addition, some protective technical measures should be adopted during the stamping process:

1. The protection of the stamping work area of ​​the stamping parts processing factory.

1. Install protective devices around the die.

2. The die is properly designed, and the die reduces the danger range.

3. Automatic or mechanical feeding design.

Second, stamping parts processing factory anti-punch protection measures.

1. Pushing hand: a protective device that is connected to the slider of the punch press and uses the swing of the baffle to push the worker’s hand out of the die mouth.

2. Swing rod protection device: a device that uses the lever principle to pull the hand.

3. Handle protection device: It is a device that uses pulleys, levers and ropes to make the hands of the staff and the slider move in conjunction.

The above is the related content of stamping die problems and protective measures. The role of die in stamping process cannot be ignored. Only by doing a good job in relevant protection work and solving problems in time can we reduce costs and improve efficiency. Hope the above will be helpful to readers.

Metal stamping parts processing, stamping parts stretch forming method

Products are drawn using stamping equipment including:

1. Tension treatment:

The plate pressing device uses the punch of the punch to pull part or all of the plate into the die to make it a bottomed container. For the drawing process of a conical (or pyramidal) container, a hemispherical container, a parabolic container, etc., the side walls thereof are parallel to the drawing direction, and the expansion process is also included.

2. Pull back processing:

That is to say, for a deep-drawn product that cannot be completed by one-time drawing, after the drawing process, the formed product needs to be drawn again to increase the depth of the formed container.

3. Reverse drawing processing:

Use the tension punch in the previous process to pull back, so that the inner wall of the workpiece becomes the outer side and the outer diameter is reduced.

4. Thin stretch processing:

The shaped container is extruded through a punch into a female cavity that is slightly smaller than the outer diameter of the container, thereby reducing the outer diameter of the container with the bottom, reducing the wall thickness, eliminating offset, and allowing the surface of the container to smooth.

Precautions for processing of pressed and drawn parts

1. The shape of the metal stamping and drawing die should be as simple and symmetrical as possible, and it should be stretched at one time.

2. For parts that need to be stretched many times, under the premise of ensuring the necessary appearance quality, there should be possible stretch marks on the appearance.

3. In order to ensure the installation requirements, the side wall of the extension piece should have a certain inclination angle.

4. The distance between the bottom surface of the telescopic piece or the hole edge of the flange and the side wall should be appropriate.

5. The bottom-wall surface, flange and wall surface of the drawing piece, and the radius of the four corners of the rectangular part should be appropriate;

6. The ruler, inner and outer shape of metal punching and drawing parts cannot be uniformly marked.

The above content is related to the processing of metal stamping parts. In fact, in the final analysis, the quality and performance of the stretched parts are the key, and the later use is also a basic principle. Of course, in the process of processing and production, the product will not have any defects, what we have to do is to reduce these failure rates to a very small amount. Thereby, the production efficiency of the stretched parts is improved. Hope the above content is helpful to readers.

What types of stamping dies are important for stamping parts processing?

The production process of stamping die is the whole process of processing raw materials into stamping die parts required by design drawings through casting, forging, cutting and special processing, and then assembling the die according to technical requirements such as design and process procedures. Stamping die is an indispensable die in stamping production. Stamping dies can be basically divided into simple dies, continuous dies and composite dies.

1. Simple die

A simple die can complete a process with only one punch in the punch. That is, the simple die for blanking or punching, when the assembly drawing of the simple die is working, it is fed along the two guide plates 9 on the die and hits the positioning pin 10 . When the sheet is pressed down, the stamping (or scrap) enters the concave hole and the strip is clamped and up together with the punch. After the strip material contacts the discharge plate (fixed on the die), it is pushed down, so that the strip material continues to enter, and the above steps are repeated to flush out the second one.

2. Continuous casting mold

In one stroke of the stamping machine, the die is called a continuous die, in which multiple stamping processes are done simultaneously in different parts of the die. In operation, the DING pin 2 is aligned with the pre-punched positioning hole, the upper die moves down, the punch 1 is blanked, and the punch 4 is punched. When the upper die returns, the stripper plate 6 pushes out the rejects from the punch. At this time, the blank 7 is advanced again, and the second punching is performed. In this cycle mode, the distance of each feed is controlled by the baffle pin.

3. Double die

In one stroke, a die that completes several punching holes in the same die at the same time is called a compound die. The biggest feature of the combined mold is that there is a punch 1 in the mold. The outer circle of the punch and concave die is the cutting edge of the blanking punch, and the inner hole is the deep drawing die. When the slider moves along the convex and concave die and down, the strip falls into the concave and convex die 1 and the blanking die 4. The blanking part is held up by the drawing punch 2 in the lower die, and when the slider continues to move downward, the die moves downward to draw deeper. The ejector 5 and the discharger 3 push out the die by stretching 9 when the slider returns, which is suitable for the compound die of mass and high-precision stamping parts.

The research and development of this simple die has important practical value for cold stamping production. The reason is that compared with simple molds, it has fast production time and low manufacturing cost, which provides a more economical and effective way for trial production of some new products and mass production of stamping parts with low requirements.

Stamping die is an indispensable process equipment for stamping production. It is a technology-intensive product. The quality, production efficiency and production cost of stamping parts are directly related to the design and manufacture of molds.

As one of the important indicators to measure the level of product manufacturing in a country, the technical level of mold design and manufacturing determines the quality of the product to a large extent. advantages and new product development capabilities.

What are the types of stamping dies mentioned above that are important for stamping parts processing? Related content, in modern industrial production, various molds are widely used in production. Mold is an important process equipment for casting, forging, stamping, plastic, rubber, glass, powder metallurgy, ceramics and other industries. I hope the above is helpful to readers.

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.