The most complete stamping dies information
★The concept of stamping dies
Stamping dies, also known as a die, metal mold, metal stamping die. It refers to a pressure processing method that uses a mold fixed on a punch press or a press to apply a certain pressure to a metal or non-metal plate to separate or shape the material, thereby obtaining a part with a certain size requirement and an appearance quality. There are many types of molds, which are mainly for metal stamping dies.
The products processed by the mold are the same in size and appearance, because there is no difference, because of rapid molding, high production efficiency, stable product quality, accurate accuracy, high material utilization, simple operation, low labor intensity, and operator The technical requirements are not high. As long as the general people come in and follow others for a day or two, they will be able to get started soon. Some even can learn in a few minutes without a day or two.
★Structure introduction of stamping die
Molds are typically assembled from several stencils and parts as well as standard parts.
The general stamping die structure, the specific template from top to bottom (including the code number) is:
The template for the upper mold is:
Upper pallet, upper footing, upper die set (UPU), upper backing plate (UBU), upper holder (PHU), stop plate (PPS), stripper(PSU);
The template for the lower die is:
Die plate (DIE), lower board (LBD), lower die set (LPD), lower pad, down parallel;
Other uncommon templates:
Upper cover plate (CVU), the backup plate, upper template, lower stripper plate, lower stop plate, lower backing plate, form punch, form die, etc.;
Some mold components are:
The insert of the upper mold, into the block: the plywood into the block, insert, the stripper, the punch, etc.;
The insert of the lower die, into the block: the lower die into the block, the lower die edge, etc.;
Standard parts: spring, hexagonal screw, shoulder screw, wire spring, contour set, guidepost, guide bushing, ejector sleeve pin, lifter pin, dowel pin, top pin, etc.
Non-standard parts: external positioning, internal positioning, pitch positioning, outer limit column, inner limit column, etc. If you need mold parts, please contact DG MF Mold Components Co., Ltd.
Stamping die number, generally written like this (for example):
Engineering model: 90-KNMF0125RAH, 90-KNMF0125RAA, 90-KNMF0125RBB
Continuous mode: 90-KNMF0125SAA, 90-KNMF0125SBB
The latter RAH, R stands for engineering mode, H stands for a total of eight sets (from AH, RAH, RBH...RHH respectively), A stands for the first set; RAA or RBB stands for riveting molds, such as riveted studs, riveted shrapnel Wait;
The SA in SAA and SBB represents the continuous mode, 0125 represents the mold number, the front F represents the year, and the mold produced in which year is indicated by the number of the year, such as F0125, G0125, if F represents 2010 Then, the mold F0125 produced in 2010 can be referred to as 125 mold, and the next mold produced in 2011 is the beginning of G. At this time, you will say 125 molds, and most of them think it is G0125 mold.
Others such as the upper splint (PHU), the number is 90-KNMF0125SAAPHU, the splint into the block 90-KNMF0125SAAPHPA001;
If there are two segments in this continuous mode, use A and B to indicate after the 90-KNMF0125SAAPHU number, then the first segment of the splint should be 90-KNMF0125SAAPHUA, the second segment 90-KNMF0125SAAPHUB, the splint into the block 90-KNMF0125SAAPHPA001, 90 -KNMF0125SAAPHPB001;
Lower template (DIE): 90-KNMF0125SAADIE, 90-KNMF0125RAHDIE
★ Common materials for stamping and selection
The nature of the materials used in stamping is closely related to stamping production. Its properties directly affect the stamping process design, stamping quality and product service life, as well as the organization of balanced production and stamping parts production costs.
When selecting the material of the stamping, it is necessary to consider not only the performance but also the stamping and subsequent process performance requirements. The basic requirements for stamping processing are as follows.
1, with good stamping performance
For the forming process, such as stretching, bending, stepping, convex hull, etc., the material should have good stamping and forming properties, that is, it should have good crack resistance, good moldability, and shape, otherwise the product is prone to deformation. , rupture, etc., causing difficulties in repairing the mold. For the separation process, the material is required to have certain plasticity.
2, with a high surface quality
The surface of the material should be smooth and flat without damage. The material with good surface quality is not easy to be broken during molding, and it is not easy to scratch the mold, and the surface quality of the workpiece is also good.
3. The thickness tolerance of the material should conform to the national standard.
Because a certain mold gap is only suitable for materials with a certain thickness range, if the material thickness tolerance is too large; not only directly affects the quality of the workpiece, but also may lead to the appearance of waste. In the process of correcting bending, shaping, etc., there is a possibility that the mold or the press is damaged due to excessive thickness deviation. For mold parts, please contact DG MF Mold Components Co., Ltd.
Common materials for stamping and selection
1. Common materials for stamping
The most commonly used materials in stamping production are metallic (including ferrous and non-ferrous metals), but sometimes non-metallic materials. 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 are mainly pure copper, brass, bronze, aluminum, etc.; non-metallic materials There are cardboard, laminate, rubber sheet, plastic sheet, fiberboard, and mica.
The supply state of metal materials for stamping is generally various types of sheets and strips. The sheet material can be used for the production of engineering molds, and the strip material (rolling material) can be used for the production of continuous molds, and can also be used for the production of engineering molds. The size of the sheet material is large, and it can be used for stamping large parts. The sheet material can be cut into strips according to the sample size and used for stamping of small and medium-sized parts. The strip material (also called coil material) has various widths. The unfolding length can be up to several tens of meters, and it is supplied in a roll shape, which is suitable for automatic feeding of continuous mold mass production.
For the grades, specifications, and performance of various materials, please refer to the relevant manuals and standards. For mold parts, please contact DG MF Mold Components Co., Ltd.
2. Reasonable selection of stamping materials
The selection of stamping materials should consider the use requirements of stamping parts, stamping process requirements and economy.
(1) Reasonable material selection according to the requirements of the use of stamping parts
The material selected should be such that the stamped part works properly in the machine or component and has a certain service life. To this end, the selected materials should meet the requirements of the corresponding strength, stiffness, toughness, corrosion resistance and heat resistance according to the conditions of use of the stamping parts.
(2) Reasonable material selection according to the requirements of the stamping process
For any type of stamping, the material selected should be able to stably form a qualified product that does not crack or wrinkle according to the requirements of its stamping process. This is the most basic and important material selection requirement. To this end, the following methods can be used to select materials.
1 test. According to the previous production experience and possible conditions, several kinds of sheets that can meet the requirements for the use of stamping parts are selected for trial-and-shoot, and finally, one which has no scrap rate or low wrinkle is selected. The result of this method is relatively straightforward, but with greater blindness.
2 analysis and comparison. Based on analyzing the deformation properties of stamping, the maximum degree of deformation during stamping is compared with the limit deformation allowed by sheet metal forming performance, and based on this, the board suitable for the stamping process requirements of the parts is selected.
Besides, the same grade or plate of the same thickness, there are cold rolling and hot rolling. Among the domestically produced plates, the thick plates (t>4mm) are hot-rolled sheets, and the thin plates (t<4mm) are cold-rolled sheets (also hot-rolled sheets). Compared with hot-rolled sheets, the cold-rolled sheets are accurate in size and small in deviation.
The surface defects are small, the light is bright, the internal structure is dense, and the punching performance is better. (Note: t generally represents the thickness in the mold. For example, the thickness of the template and the thickness of the material can be expressed by t.)
(3) Reasonable material selection according to economic requirements
The selected materials should be as low-cost, convenient, and economical as possible to meet the requirements of use performance and stamping process, to reduce the cost of stamping parts. For mold components, please contact DG MF Mold Components Co., Ltd.
★ Classification of stamping dies
The classification of stamping dies, generally, we can simply divide it into two types, namely engineering molds and continuous molds;
The engineering mold can be divided into the composite mold, tensile mold, riveting mold, etc. The structure and function of these molds are briefly introduced below;
Engineering mold: Also known as "single-process mold", it refers to a mold that can only complete one stamping process in one stroke of stamping. After the project is finished, it is necessary to take the product out of the mold manually or with a robot, and then put it into the mold of the next station to continue production until the last process of the mold is finished, and the whole product is completed. The mold is simple to repair, but it takes time and labor to produce, requires a lot of labor and time costs, and has a high product scrap rate.
Compound mold: Common composite mold structures include composite blanking, composite stretching, etc. This mold structure is slightly different from other engineering mold structures. The punch (also called the male die or the punch) is designed in the lower die, and the other templates are the lower clamp (fixed punch), the lower stop and the lower strip (outer). It is composed of the female mold (or knife-edge), the inner stripping plate and the upper backing plate. The inner sleeve is hung on the upper backing plate and then pressed with a rod or a spring. For example, the composite mold used for the blanking is generally removed from the master mold by 0.50 mm, and may not be lower than the master mold, or the mother dies edge may be easily collapsed or not removed. The force of the inner strip should be large enough to push the product out of the mother mold. Generally, if the material is thick, we have a nitrogen gas spring.
Continuous mode: Also known as “grading die”, it refers to the mold that completes two or more stamping processes at different stations at the same time during the one stroke of stamping. This kind of mold maintenance is difficult and requires experience. The rich fitter masters operate, but the production is very efficient. If you play fast, you can produce thousands of products in one hour, saving labor and time costs, and the product scrap rate is low.
★Spring compression and calculation
In a set of stamping dies, more elastic materials are needed, including various springs, superior rubber, and nitrogen springs. Different elastic materials are used according to different needs. For example, bending and punching can be done with ordinary flat springs, such as brown springs, also known as brown springs; if the power is not enough, add a nitrogen spring, of course, the cost is higher; superior glue is generally used for drawing molds. , plastic mold, or flatness.
The deep drawing mold is very good with the excellent glue, of course, you can also choose the nitrogen spring. Others such as top pins, floats, dual-purpose pins, etc. generally use wire springs or yellow springs, as long as they can be stripped off, do not push the product out of the print, the top deformation is good. The characteristic of excellent glue is that the strength is relatively balanced, but its life is relatively short, so it is generally less used, usually more commonly used nitrogen spring. The whole flatness is used for a lot of glue.
The spring includes a flat wire spring, a wire spring, etc. The purpose of the spring is to remove the material and press the material, and the magnitude of the spring force is related to whether the mold production is smooth or not, and whether the product is qualified or not. The spring force is small, which may cause various problems such as product deformation, mold not to be stripped, products not good to be taken out from the mold, strips, knife edges, and punches.
Flat wire springs are generally divided into two colors: brown, green, red, blue, and yellow. The strength is also weakened in turn. The colors are different, the strength is different, and the compression is different.
There is a soil method to calculate the compression of the spring. That is, I just entered the factory to learn the mold soon. I don’t know much about the mold. My master taught me: measure the total height of the spring beforehand and put the spring in the vise. , lock, and then use a caliper to measure the length of the spring after the clip is clamped, then subtract the total length from the spring, and then divide by the total length. This method is universal for any spring, such as the length of the brown spring is 60mm. After being clamped by a vise, there should be about 45.6 left, then you subtract 60 from 45.6 to 14.4, and then divide 14.4 with 60. The result is equal to 0.24, which is the amount of compression.
According to different production times, such as 1 million times, 500,000 times, 300,000 times, the larger the compression amount, the shorter the spring life, the shorter the life of the mold (of course, the spring can be replaced if it is broken), the mold After a period of production, the spring may be weak, and the spring with a poor quality may break in the mold. Generally, the compression amount of the spring is calculated according to 300,000 times, that is to say, the mold may be incapable of hitting 300,000 times of springs. Of course, the general stamping dies life is not so long, and it can also be calculated according to the maximum compression amount, according to the maximum compression. If the amount is calculated, it can only guarantee that the spring does not explode inside the mold. The mold is pressed a little and it is good for product flatness. For mold accessories, please contact DG MF Mold Components Co., Ltd.
The specific compression amount is as follows:
Color 100 times 500,000 times 300,000 times Maximum compression
Brown spring 16% 18% 20% 24%
Green spring 19.20% 21.60% 24% 28%
Red spring 25.60% 28.80% 32% 38%
Blue spring 32% 36% 40% 48%
Yellow spring 40% 45% 50% 58%
The maximum compression (how much this spring can be pressed), the maximum compression of the spring is equal to the free height of the spring multiplied by the maximum compression ratio of the spring, such as a brown spring, the length is 60mm, then its maximum compression is: 60 * 24% About 14, this spring can be pressed down to 14 mm, its maximum stroke is 14 mm, the stroke of the mold must be less than 14 mm, more than 14 mm, the spring may fail, deform, and possibly hit Broken in the mold, or the mold is explosive, the press cannot be pressed and so on.
Before the mold is assembled, that is, before the mold is installed, it is necessary to calculate whether the compression amount of the spring is appropriate, so that when the mold is tested, there is no need to worry that the mold will have problems or explosions.
★ Determination of the gap value of stamping die
For the determination of the blanking gap value, empirical formulas and charts are generally used.
People who have worked on stamping die fitters and stamping die design for a long time, because of their rich experience, naturally, understand and know a variety of different products, including it's material, size and appearance accuracy requirements, and how to design the mold to be able to produce smoothly. Out of qualified products, how to reduce the number of mold repairs, mold repairs, etc., get the product map, the heart will naturally think of this mold structure is probably what it looks like, all kinds of values are in mind.
★ Determination of the gap value of stamping die
For the determination of the blanking gap value, empirical formulas and charts are generally used.
People who have worked on stamping die fitters and stamping die design for a long time, because of their rich experience, naturally, understand and know a variety of different products, including it's material, size and appearance accuracy requirements, and how to design the mold to be able to produce smoothly. Out of qualified products, how to reduce the number of mold repairs, mold repairs, etc., get the product map, the heart will naturally think of this mold structure is probably what it looks like, all kinds of values are in mind.
The gap between the punch and the knife-edge has a great influence on the quality of the stamping part and the life of the stamping die. Therefore, when designing the stamping die, it is necessary to choose a reasonable gap to ensure that the cross-section quality and dimensional accuracy of the stamping part meet the requirements of the product, the required punching force is small, and the life of the stamping die is high. However, the reasonable gaps determined from the requirements of quality, punching pressure, stamping die life, etc. are not the same value, but close to each other.
Considering the deviation in the manufacture of stamping dies and the wear in use, usually, only a suitable range is selected as a reasonable gap in the production, as long as the gap is within this range, a good part can be punched out. In the production process, the stamping die will continue to wear and increase the gap, and the minimum reasonable gap value should be adopted when designing and manufacturing the new stamping die.
Stamping dies blanking clearance, according to the experience of the factory master's research and improvement of the mold for many years, the parts with high dimensional accuracy and cross-section perpendicularity should use smaller gap value, and the section perpendicularity and dimensional accuracy are not required. Pieces should be based on reducing the punching force and increasing the life of the stamping die, and a larger gap value can be used. Its value can be calculated according to the following empirical formula:
Material thickness t < 1 mm, blanking clearance c = (3% ~ 4%) t
t = 1 ~ 3mm, c = (5% ~ 8%) t
t = 3 ~ 5mm, c = (8% ~ 10%) t
t = 1 ~ 3mm, c = ( 6% ~ 8% ) t
t = 3 ~ 8mm, c = ( 8% ~ 13%) t
The following is the theoretical knowledge in the book, the main basis is to ensure that the upper and lower cracks meet, to obtain a good section.
According to the relationship of the triangle ABC, the gap value c can be obtained as:
c =( t – h0 ) tanβ = t (1-h0/t) tanβ
Where h0 is the depth of the punctured cut; β is the angle between the direction of the maximum shear stress and the direction of the perpendicular.
As seen from the above formula, the gap c is related to the material thickness t, the relative plunging depth h 0/t, and the crack direction β. While h0 and β are related to the nature of the material, the harder the material, the smaller the h 0/t.
Therefore, the main factors affecting the gap value are material properties and material thickness. The material is harder or thicker and the gap value is larger.
★The whole process of stamping die development
How is the stamping die machined?
A complete set of stamping die development process, the first step should be that the customer sends the product map to the head of the stamping die design department, and the design supervisor confirms whether the product can be made with the technology of the department. If you can, then give the designer a plan to prepare the material. The various boards required for the mold are first bought back. The rough processing allows the thickness of the template to be ground to a certain size. Generally, the remaining amount of 50 pieces (0.50 mm) is left on both sides. After the rough processing is completed, the heat treatment is sent.
At the same time, the design department personnel opened a seminar to develop a step-by-step process pattern of the product and discharged the strip chart. A product cannot be produced in just one process and must be combined with other processes to produce a qualified product. After the product process diagram is finalized, the designer begins to design the mold.
After the design draws all the parts of the whole mold, the mold can be officially started. First, the template is ground to the correct size, then discharged, put through the hole, and then cut, cut into the hole, knife-edge, Blanking, etc., then sent to the milling machine or CNC Machining processing the countersunk head, giving way, etc., and finally by the quality assurance test, if it is unqualified, it will be returned to the responsible department for further processing. After passing the test, it can be sent to the warehouse for storage.
Finally, the fitter takes the warehouse from the warehouse and begins preparations before assembly, such as chamfering, burrs, rust, confirming the size, checking whether the parts are in place, whether there are holes and holes, whether the screws are missing, etc. When the parts arrive, you can start to assemble the molds for a while. When you have finished the mold parts, the molds are almost ready to be installed. It is much more time to start loading than the parts.
After the mold assembly is completed, the mold is tested and the mold is turned on until the mold can produce the product with the dimensional accuracy and appearance quality compound requirements, and then the customer is sent to sign the sample. The customer confirms that all the work of the mold is officially completed. , just wait for the machine to produce. In the future, it will repair and repair the mold.
★ What is a punch? How is the length of the punch calculated?
How is the length of the punch calculated?
First, let's study what is a punch? What role does the punch play in the stamping die?
The punch refers to a punch mounted on the splint, which generally functions as punching, cutting, bending, stepping, convex hull, salad, bud, rivet stud, etc. These may be referred to as "punches" for short.
The length of the punch is equal to the thickness of the splint + the thickness of the baffle plate + the thickness of the stripper + the thickness of the material + (1 ~ 2) two mm;
The length of the 90-degree bending punch is equal to the thickness of the splint + the thickness of the baffle plate + the thickness of the stripping plate + the thickness of the material plus one or two millimeters, and the appropriate adjustment according to the need during the test; other angles The front of the bending punch generally has a certain angle. It should be flexibly applied in the calculation and reasonably calculated according to the angle.
The length of the punch having the difference is equal to the thickness of the splint + the thickness of the baffle plate + the thickness of the stripper plate + the height of the step difference.
These are just dead methods. Actual applications should be determined according to the situation. I will not explain them here. For mold components, please contact DG MF Mold Components Co., Ltd.
★Composite mold, what is a composite mold?
The composite mold refers to a mold that completes a plurality of stamping processes in one stroke of the press. The process of using the composite mold structure includes plane blanking, blanking, cutting, bending, forming, shaping, stretching, burring, squeezing, flanging, etc., which can be flexibly selected according to actual conditions. Generally, it is possible to use four or fewer processes, and too much may make the mold manufacturing difficult, the mold strength is lowered, and it is easy to be damaged, increasing the frequency of mold repair and an increase in the cost of the mold. The use of composite mold production can improve product accuracy and increase production efficiency.
For example, if you make a washer, you can use two pairs of molds to punch and fill the material separately. The punching is the hole in the middle. The blanking is to punch out the shape. If you use a pair of molds to complete it once, it is compound mold. There are also stretching, trimming, etc. in the single-step mold. As long as one pair of molds complete two or more steps at a time, it is called a composite mold.
The structure of the composite die that is blanked or bent upwards: the punch (also called the male die or the punch) is designed in the lower die, and the other templates are the lower clamp (fixed punch), the lower stop and the lower The stripping plate (outer stripping), the upper mold is in turn composed of a female mold (or a knife-edge), an inner stripping plate and an upper backing plate, and the inner sleeve is hung on the upper backing plate using a contour sleeve, and then is pressed with a rod or a spring. .
The composite mold used for the blanking is generally removed from the master mold by 0.50 mm, and may not be lower than the master mold, or the mother dies edge may be easily collapsed or not removed. The force of the inner strip should be large enough to push the product out of the mother mold. Generally, if the material is thick, we have a nitrogen gas spring.
The composite mold belongs to a mold structure, which can be classified as an engineering mold. Because it is used in engineering molds, generally, the entire engineering mold adopts a composite mold structure.
The upward molding of the continuous mold, the upward bending, the upward convex hull, the upward convex bump, and the upward warping angle are generally also adopted as a composite mold structure.
★When the composite mold punches the convex hull, is the punch higher than the detachment?
I received a question from a classmate today, saying: When the composite mold punches the convex hull, is the punch higher than the detachment?
The answer is yes, how can I punch the convex hull without going out of the stripper?
I suggest that this classmate should review what is a composite model? How is the length of the punch calculated? If you figure this out, you will naturally understand how to answer this question.
When the composite mold structure is punched, the length of the punch is equal to the thickness of the splint + the thickness of the baffle plate + the thickness of the stripping plate + the height of the convex hull.
That is, when the mold is killed on the punching machine, the punch must be higher than the stripper plate. How much higher? Of course, how high the convex hull requirement is, how high it is here, must be within the required accuracy of the allowable convex hull height.
When the mold is opened and the mold is opened, the punch does not bear any force. The convex punch must be shorter than the stripper and retracted into the stripper. Otherwise, the stripping stroke should be increased.
When the composite die punches the convex hull, when the mold is knocked down, the stripping plate must be pressed first, and the pressing force is sufficient, and then the convex hull is punched, otherwise, the product may be deformed and the convex hull size is unstable.
★The material and function of the stamping die template
The general stamping dies are made up of:
Upper and lower pallets, upper and lower pads, upper and lower mold bases: generally made of A3, Q235 and other "soft materials", to support the entire mold, easy to frame mold, blanking and so on.
Upper and lower stencils: the upper and lower stencils function as fixed edge, into the block, into the sub-feed, top pin, etc. External positioning, internal positioning, floating guide pin, dual-purpose pin, guide plate, floating block are also fixed under The hardness of the template on the template must be about 58-62 HRC. The hardness is too low, which will affect the quality of the blanking. The thickness is generally 25 to 40 mm. Some knife edges are cut directly on the template, that is, the knife-edge is directly cut on the template. If this is done, if the knife edge is missing, collapsed, worn, and burrs, it is not easy to repair the mold; another method is to dig into the block. That is, the knife-edge is dug in a block (this block is called "the lower die edge"), and then the lower die edge is loaded into the lower template. The height should be as high as the lower template. The error should be within plus or minus 1 to 2, preferably within plus or minus 0.005 mm. Generally, the grinder master or the fitter master can achieve it. Too many will print the product (print).
The upper and lower pads are generally made of Cr12. According to the needs, the thickness of the upper and lower pads of each set of molds is different. Look at the punching force. If the punching holes are small, the upper and lower pads can be made thinner by 8~10mm. If there are more punching holes, it is necessary. Appropriately thicker, generally about 17 ~ 20mm. The lower pad is mainly a blanking hole, a spring through the hole, a screw through-hole, a guide column vent hole, and the like.
The upper and lower splints, the upper and lower splints are mainly used for fixing the punch, the punch, and the guidepost, generally 17 to 20 mm. The material hardness of the stamping die plywood generally does not need to be particularly high. Generally, the soft material can be used, but it is too soft. It is possible to pull the hanging platform of the punch directly into the splint and pull the splint. Therefore, in designing the stamping die, it is necessary to consider the structure of the die, the material selection of the die material, the tonnage of the selected punch, the size of the punching gap, etc., in order to make the processed workpiece burr smaller. To extend the life of the mold.
Stop baffle, stripper plate, etc., the top plate can be used with Cr12, but the stripper plate must use hard material such as Cr12Mov. The stop baffle and the stripper plate are locked by the M6 or M8 screws and then locked together. The stop baffle mainly has some through holes, punch through holes, guidepost through holes and the like. The stripping plate mainly functions as a material for stripping, pressing, and guiding punches. Generally, we use a stripper to guide the punch, guidepost, and punch. If the aluminum material is produced, it is easy to jump into the stripping plate, pull the punch, or catch the punch, pull the punch off, pull out the stripper, etc., so you must use the stop plate to guide the punch. , and the stripping board is properly enlarged 10 to 20, or the stripping plate is used for two sections, the upper section is used for guiding, and the lower section is also 10 to 20 unilaterally enlarged. The thickness of the stop baffle is generally 8 to 17 mm, which is also based on the amount of punching and the amount of force to be received; the stripping plate is generally 20 to 25 mm thick.
A die, punch, also known as a punch or knife-edge, is used to flush, cut, or cut, puncture, or stretch excess material. Such as: stretching punch, bending punch, slider inserting the knife, punching salad punch, punching punch, pumping bud punch, riveting die riveting punch and so on. The material of the die punch requires high hardness, and the commonly used die punch materials are Cr12Mo1v1, Cr12Mov, Skd-51, Skd-11, W6Mo5Cr4V2 (tungsten steel) and the like.
Digging: The staff used to make molds is used to refer to the meaning of the wire cutting frame. For example: digging a knife, digging a block, etc.
Soft material: In the stamping die, it refers to the die steel with hardness of about HRC35 and relatively low a hardness, such as 45# steel, A3, Q235 and so on. You can knock out a pit with something that is slightly higher in hardness. This material is very soft, so it is used to be called "soft material" because it has better seismic performance and is generally used for stamping. Upper and lower pallets of the mold, upper and lower legs, upper and lower mold bases.
Hard material: In the stamping die, it refers to the hardness of the mold (after heat treatment) in the HRC 58 ~ 62 or above die steel, such as Cr12, Cr12Mo1v1, Cr12Mov, Skd-51, Skd-11, W6Mo5Cr4V2 (tungsten steel), these The hardness of the steel is very high (but it is also brittle. If you don't pay attention, it may be collapsed by you, 55). It is generally used to make stamping dies, punches or other parts requiring high hardness. For mold parts, please contact DG MF Mold Components Co., Ltd.
★ Three views of stamping die
Three views of stamping die. Whether it is a stamping die fitter, or a stamping die design, or CNC operation, CNC programming, and grinding machines, milling machines, etc., as long as it is related to machining, must have the ability to read pictures, this is Indispensable, if you can't even understand the picture, how do you process the part?
View: Observe the geometric pattern of an object from different directions.
For example: when an object is placed in front of you:
1. From the front, the resulting geometry is called the main view; from the back, the resulting geometry is called the top view;
2. From the front left side, the resulting geometry is called the left view; from the right side, the resulting geometry is called the right view;
3, from the top down, the resulting geometry is called the top view, from the bottom up, the resulting geometry is called the bottom view;
4, in order to make the graphic expression more accurate, more understandable, easy to understand, sometimes also need to draw a cross-sectional view, full-section view, half-section view, section view and so on. The cross-sectional view is the cut-away view, the graph you see; the full-section view: the graph that is completely cut away; the half-section view is the geometry that is cut in half (not all cut open), and the cross-section is Imagine that the object breaks from here, and then the view you see after the break is graphically represented. This is the section view.
Can you draw the geometry represented by these views in three-dimensional painting?
Let's talk about the three views below.
The basic law of the three views: long alignment, width, and height.
Long alignment - the length of the main view and the top view are aligned.
Equal width - the width of the top view and the left and right views are equal.
High level - the high level (equal) of the main view, left view, and right view.
★Compressed materials for stamping dies
Commonly used stamping materials for stamping dies (also known as metal dies) are:
Aluminum: aluminum material, general appearance parts are more aluminum, such as notebook or netbook keyboard, other accessories, etc.;
Galvanized sheet: The surface of the cold-rolled sheet is coated with a zinc layer, commonly known as a galvanized sheet. Galvanized sheets have SECC, SGCC, etc., and galvanized sheets are rust and corrosion-resistant. The price is relatively high. The general plate thickness is 0.4~3.2mm. Its characteristics are excellent coating, good fingerprint resistance, good corrosion resistance and maintain the processability of cold-rolled sheets. Generally, the thickness of the chassis and the lower cover is 0.80 mm of SGCC material. Medium hardness, slightly higher than aluminum hardness, slightly softer than stainless steel. The SGCC material is relatively hard and the tensile properties are not very good. If this material is used for stretching, the die and the punch must be thrown very brightly, otherwise, it is easy to crack and crack.
Stainless steel: It can be used to produce shrapnel and exterior parts of various sizes. For example, the shrapnel with various interfaces at the back of the desktop computer case is made of stainless steel and then produced by stamping die. The material of stainless steel is relatively hard. Sometimes the mold cannot find the gasket. The stainless steel material can be used for an emergency. The punch and the knife-edge of the stainless steel need regular maintenance to ensure the smooth production of the mold. Otherwise, it is often necessary to repair the mold.
In general, the gasket needs to use the spot welder to place the gasket on the part, otherwise, it will be more troublesome when the mold is removed next time. Some factories do not allow the use of gaskets. At this time, it can be burned by using welding, and after grinding, the required size can be ground by a grinding machine.
Commonly used stainless steel materials are SUS301, SUS304, and the like. SUS200 series (including 201, 202, etc.)
SUS300 series (including 301, 304, 310S, 321, 316L, etc.) and
SUS400 series (including 409, 410, 420J1, 420J2, 430, 436L, 444, etc.)
Tinplate: Tinplate? Is it a little dizzy? I was listening to the master in the factory and said that this is a tinplate. I also mistakenly thought it was "a tinplate." wrong. In fact, I can't tell the difference. Anyway, the pronunciation is tinplate. Simply think that it is a mahjong iron! The elongation performance of the tinplate iron is relatively good, the hardness is not high, and it is relatively soft. Generally, the more complicated curved surface stretching is suitable for the use of the tinplate iron material, and it is not easy to crack. Such as the cover. Some small shrapnel and so on.
Tinplate, in which Sn is a coating, tinplate, also known as tinplate, is a common name for electroplated tin steel sheet, abbreviated as SPTE, which refers to cold-rolled low-carbon steel sheet or steel strip coated with commercially pure tin on both sides. Tin mainly acts to prevent corrosion and rust. It combines the strength and formability of steel with the corrosion resistance, solderability and aesthetic appearance of tin in a material with corrosion resistance, non-toxicity, high strength, and good ductility. For mold parts, please contact DG MF Mold Components Co., Ltd.
★What is pitch positioning?
What is the pitch? What does pitch positioning mean?
Pitch, as the name suggests, refers to moderation, and "pitch" refers to controlling distance. Then the pitch positioning is the meaning of positioning by controlling the distance. Control the distance of feeding, so as not to send more, misdelivery, damage the mold, or produce defective products.
In stamping dies, pitch positioning is typically used in continuous dies.
Continuous molds generally have special automatic feeders. They are not used for manual feeding because sometimes the delivery is not accurate, resulting in a high scrap rate, and the automatic feeder can avoid this risk. Moreover, only the small factories use manual feeding, and the slightly larger factories are equipped with automatic feeders. Manually only need to place the material on the automatic feeder as required, and then set it up.
However, the automatic feeder is not necessarily so accurate, and sometimes there will be small errors, and the pitch positioning plays a very important role.
At the beginning of the strip, the strip first comes in from the very beginning of the continuous mold, then punches two holes (positioning holes), then passes through the knife, passes through the knife, cuts the edge here, The strip is cut off and the strip is blocked by the pitch to prevent misfeeds.
Behind is pitch positioning. Pitch positioning is generally made at right angles here. Think about it, what if the front cut edge is also a right angle? The trimming is a right angle, then the punch must also be made into a right angle, because the right angle is a sharp corner, and the general punch material is very brittle, although the hardness is very brittle, it is easy to collapse, after many productions, the front That little sharp corner may not be there. Is it 90 degrees cut out at this time? Even at 90 degrees, there will be a lot of burrs, and when it comes to pitching positioning, it will be inaccurate, and the products that are printed will be inaccurate.
Do you need to keep sharp corners where the pitch is in contact with the material?
Of course, you need it! Other useless places can be chamfered to prevent scratching and scratching the handle. But this place must not fall. If you lose the pitch positioning, you need to re-weld it and then grind it at right angles. If you think it's too sharp, you can scrape it with a sickle, but don't overdo it.
Because the feeding force of the feeder is generally very large, and the cutting edge is generally only cut off a narrow point. If the corner is inverted here, if the material is thin, it is said that the material will directly rush into the mold beyond the pitch positioning. At this time, the pitch positioning has no effect.
Generally, the continuous die like a large point is used for the dual-purpose pin + pitch positioning block, that is, the pitch positioning there is a special block, which is installed on the knife and the trimming edge, but the mold is relatively small. In the case where the material is relatively thin, such a structure is not applicable. Think about why?
Generally, when the mold is relatively small and the material is relatively thin, the pressure plate is used instead of the dual-purpose pin, because the material is relatively thin, and the feeding with the pressure plate is relatively good.
How to use the pressure plate directly to locate the pitch? Is such that. If the width of the material is 10 mm and the trimming edge is cut by two millimeters, then the distance between the first pair of pressure plates can be designed to be 10 mm (to be placed in the gap), and the cutting edge here cuts off two millimeters, then the first The distance between the two pairs of platens (that is, after trimming) can be designed to be 8 mm so that the pitch can be positioned.
★ Analysis of the reasons for the stamping die jumping waste, how to repair the stamping die
What is skipping the waste? What does swarf mean?
Jumping scrap and jumping chips basically mean that the scrap jumps up, jumps to the lower formwork, or jumps to other places. In short, the waste jumps out of the knife edge.
The punch removes the excess waste and may, due to the molder, designer, or lineman, cause some of the scraps that had been removed to jump out of the lower die. Think about how dangerous it is. one thing.
If you scrape a few products, it is very serious that you may damage the mold. It is very serious that you may hurt people. It is terrible to think about it. This is the case with molds, because carelessness is done, and there are many lost hands or disabilities. Unless you do mold design, or something else. As long as you deal with the mold, the danger is everywhere!
Let's analyze the causes of the scraping of the stamping die and the method of defense.
(1) Reasons for causing jumping waste (shaking)
1. The influence of the shape of the punched scrap or the blanking piece is too simple and the weight is too light, so it is easy to be brought up by the punch;
2, magnetic reasons, the punch, or the knife edge is magnetic, it has magnetic, because of the grinding, impact changes caused by the magnetic, etc., it is easy to absorb the waste, especially iron-related materials, such as tinplate, SECC , SGCC, etc., the mold parts of these materials must pay attention to demagnetization, otherwise the mold will always be chipping, always need people to repair the mold, this is an annoying thing;
3, the impact of the punching gap, small gap or large gap may cause the burr to return to the mold surface with the punch, processing accuracy is not enough, the impact of a processing error.
4, the impact of the punching speed, the speed is too fast may cause the punch and the inner wall of the knife edge and waste to form a piston, which causes vacuum adsorption phenomenon, that is, the punch sucks the waste from the lower die edge. In this way, you can make the design dig a small hole in the middle of the punch, and the corresponding groove should be made on the pad to allow the air to circulate without causing vacuum adsorption. Or make the edge of the punch into a plane, the possibility of not a plane adsorption will be smaller.
5, the selection and use of cutting oil is not appropriate, the oil is added more, or the added oil is too sticky, the waste is absorbed on the punch and cannot fall, resulting in jumping chips;
6. The sharpness of the embossing die edge is too sharp, the light is thick and the burr is small, and the friction with the cutting edge die is small, and it is easy to be absorbed by the punch; of course, you can only think of other ways to repair it. With the mold, it is impossible to get up and down from the knife.
7, the impact of the length of the punch, generally we say that the "punch" length of the punch is equal to: the thickness of the splint + the thickness of the stop baffle + the thickness of the stripper + the thickness of the material + (1 ~ 2) two millimeters, as long as this meets this The length is ok, but if it is too long, it will start to rush without pressing the punch, which will easily cause the punch edge to wear out. Is it too short? The scrap is not completely flushed into the slope or small section below the knife-edge, and it is easy to jump up.
8, the reason of the lower die edge, because the lower die edge generally has a slope or step, the general slope is 3 ~ 5 °, according to actual needs, mold strength comprehensive consideration. Too much grinding, resulting in increased punching clearance, resulting in chipping;
9, other reasons, such as foreign matter stuck to the material is brought into the mold;
10. If the punch is large enough and strong enough, you can also dig a hole in the middle, lock the screw behind the buttocks, stop the screw + spring + top pin, push the waist down, the top pin is higher One or two millimeters of the surface of the punch is good. If it is too long, it may deform the top of the product.
11, can also be used in front of the punch with 502 a little glue on the top, or burn a 坨 welding, welding a small point up, of course, this punch is large enough, welding technology is good enough, otherwise it will burn the punch Broken, it has an impact on the strength of the punch. For mold parts, please contact DG MF Mold Components Co., Ltd.
★Quality analysis of stamping die tensile parts
Quality analysis of stamping die tensile parts
During the stretching process of the product, there are mainly several problems in the stretching parts: wrinkling, cracking, uneven thickness, surface scratches, shape distortion, rebound, and the like. Among these phenomena, wrinkles and cracking have the greatest impact on product quality. These two problems of products are inevitable and must be adjusted. Products with these two problems can only be scrapped. Customers are not allowed.
During the stretching process, the surrounding edge portion of the material is too tangential, causing the material to lose stability so that the product is tangentially formed along the edge to form rugged wrinkles, called wrinkles.
When the wrinkling is severe, it will also cause the material to pass through the gap between the die and the punch during the stretching process, increase the tensile deformation force, and even cause the crack.
The instability phenomenon depends on both the tangential stress of the edge of the material and the thickness of the tensile member.
To prevent wrinkles, it is possible to use a crimping ring. In some places, it is called a presser bar. It is a meaning that a raised rib is placed around the material without affecting the back process of the product. The advantage of this is that the stretched product will be fuller and will prevent wrinkles.
The blanking force needs to be adjusted relatively when trying the mold. Generally, the design is not so reasonable. It is necessary to adjust the height of the pressure rib according to the product that is punched out. If the blanking force is too large, the friction between the material and the die and the bead ring will increase, which will make the wall of the material thin or even crack. If the blanking force is too small, the wrinkling cannot be effectively prevented.
The second problem is cracking, which is a problem often encountered during stretching.
When the tensile stress on the wall exceeds the strength limit of the material, the product will crack, and the crack generally appears at the wall of the punch slightly above the corner.
Factors affecting product cracking are tensile properties of the material, diameter, and thickness of the material, drawing coefficient, fillet radius of the concave and convex mold, blank holder force, friction coefficient, and the like.
The radius of the fillet of the concave-convex die is too small, too sharp, it is easy to crack the product. The general method of repairing the mold is to find ways to increase the rounded corners, smooth the rounded corners, and throw a little light, it is not good. It is also possible to add oil when it is produced, especially for stretching special oil, which is very effective.
When designing stamping dies, you can increase the fillet as much as possible, as required by the customer's product requirements.
When stretching, the necessary lubrication is used, which facilitates the smooth progress of the drawing process and improves the wall thickness reduction. However, it must be noted that the lubricant can only be applied to the working surface of the die, and the lubricant should not be lubricated on the contact surface of the material, because the convex and the surface of the blank are favorable friction, which can prevent the material from sliding and pulling. Cracked and thinned.
★The technology and the processing equipment needed to repair the stamping die?
Each part of the stamping die must pass these procedures first:
First, the material is opened, and the material is opened, which means rough processing. Generally, a template must be roughly flattened by a planer, and then coarsely ground and roughed by a large water mill (grinding machine, also called a large grinding machine), leaving a certain margin (generally leaving a margin of 5 mm, the accuracy requirement is plus or minus 1 mm) )), then heat treatment is required to take the heat treatment. After the heat treatment is completed, after the finishing of the large grinding machine, the precision is required to be higher. For example, the template thickness is 25.00mm, then the precision requirement must be within plus or minus 0.01mm. Look at the role of the template, generally no difference between one or two, as long as the product is not mold-printed.
After the grinding machine has been processed, it is sent to the threaded hole, then the wire is cut, and then the milling machine, CNC, etc.
If it is a small part, it is like this: according to the size of the part, use a saw blade saw, or use a milling machine to mill, after roughing the grinding machine, the excess cutting piece is cut off, and it is almost the same to see the situation, either to cut the wire, or to the CNC. (also into a high-speed milling machine) processing, need to discharge and put a point. After the completion of the quality assurance measures.
In general, it is a planer, a lathe, a milling machine, a drilling machine, a grinding machine. These are the mold cutters who must be skilled in operation. However, the slightly larger factories basically do not use planers and lathes because they are all responsible for the processing. You don't have to worry about it at all. What is the processing equipment that must be mastered by the fitter?
Since it takes so many processing equipments to make a stamping die, how about repairing the mold? Why should the mold be repaired?
Because it is broken, it can't make a product; why is it bad? Because the designer's design is unreasonable, or the mold production time is long, the technical problems of the molder, or the carelessness of the production line personnel.
What are the main repairs?
If it is broken, repair it there. For example, if the spring force is not large enough, the design of the stripping part is not reasonable, etc., it may be necessary to replace the spring or increase the spring, or improve the stripping structure, increase the top pin, etc. Then, you need to use drilling machine drilling, or milling machine to drill the countersunk head, or it is possible to use welding, then you need to operate the argon arc welding machine, argon arc welding, etc., after burning, you may need to grind and mill. Wait.
In general, the techniques that stamping die fitters need to know are:
1, must be familiar with the working principle of various molds, and their processing accuracy requirements; a set of stamping molds for you, first you need to fully understand its structure, as well as working principles, design ideas, etc., must be familiar with each The function and performance of the parts, so that the mold has a problem, and the production is broken, it will soon be a question of where the problem is, and where to repair it. The structure of each set of molds and the ideas of the designers are different, so the repair methods of each set of molds are different, but they are similar.
2, skilled operation of grinding machines, milling machines, drilling machines, argon arc welding, processed parts should meet the accuracy requirements of the mold, planer, the lathe is basically not used, this will not have much to do with. It used to be necessary. Now that technology has developed so fast, it will not be used. There are also grinding bits, milling cutters, etc. These are also to be mastered.
3, there are discharge, wire cutting, CNC, do you know what they are doing? How much can the processing precision be achieved? When to use which one, this must be clear. It is convenient to use when it is easy to repair, saving time and improving mold efficiency.
In short, there are so many, the mold working principle understands nothing after the fear, the mold is broken, you can immediately think of what may be the problem, where to move.
If you are a designer, you need to be proficient in drawing software, solid modeling, etc., such as CAD, or UG, Pro/E, 3DMAX, Mastercam, etc., depending on the requirements of the factory, you can design the mold to be OK! CAD can be used to design simple molds. Some complex molds need to use three-dimensional aspects. Solid shapes will be more intuitive, and the mistakes will be less. After all, rely on CAD to think about it, even if you have space imagination. Strong, it is not so easy to make the complex mold structure so imaginary, cannot guarantee that there will be problems of drawing wrong, missing painting, structural errors, increasing mold processing time, resulting in increased mold transaction time, wasted time, and consumes manpower and material resources. If you are a fitter, you need to know a little about drawing software. Simply look up the length of the line, the width of the part, etc. You should. Because the mold is sometimes used, how to process and repair the mold without knowing the size of the part? For mold parts, please contact DG MF Mold Components Co., Ltd.
★The role of continuous die stripping plate pressing trough
Generally, the mold stripping plates are not designed with a pressing groove. For example, the general engineering molds do not have a pressing groove, but why do continuous molds need to design a pressing groove? Why does the engineering mold not require a press tank? Did you figure this out?
Why doesn't the engineering die to need a press chute? This is because the materials stamped by the engineering die are generally thicker, rougher, less precise, do not need to be as long as the continuous die, and the engineering mold is relatively small, the template size is not as long as the continuous die, the required size of the product The precision is not as high as that of the continuous mold, and it is easier to repair and debug. Therefore, the engineering mold generally only needs a limited position column and does not require a pressure groove. In the case of continuous mode, it needs to complete mass production, and the precision of the product is higher than that of the engineering mold. Therefore, the precision of the mold is relatively high, and the pressure groove is a method to improve the precision of the mold. Therefore, the continuous mold generally uses a press tank and a limit column to control the gap of the product strip in the mold.
Why do continuous molds need to design a press chute? Because the continuous die stripper is in contact with the lower die plate and presses the material, strong pressure does not mean that the material can be completely pressed, so the face of the continuous die and the face that touches the lower die plate will have 0.05mm to 0.08mm depth of the pressure groove (can be adjusted according to the material thickness), commonly known as "pre-pressure", the width is just a little wider than the tape, to ensure that all the material is pressed inside, so as to ensure that the tape is in the mold when cutting The gap in the middle is even, so that the material can be fully pressed when cutting, to prevent the punch and the knife-edge from being worn due to uneven pressure, and the bright belt is not neat.
Note: Because the pressure tank and the limit column are used together to control the gap of the product strip in the mold, the stripper plate is designed with a pressing groove, so when designing the limit column (some places are called the stop column, That is, the column with height limit.), this pre-compression depth should also be taken into account to reduce the adjustment time of the fitter in the mold set and speed up the progress of the mold.
For example, the product material thickness is 0.20mm, and the stripping plate pressing groove can be designed to be 0.05mm. The height of the limiting column on the lower template can be designed as lower template thickness + (0.20mm-0.05mm), false as template thickness If it is 25.00mm, then the height of the limit column on the lower template can be designed as 25.00mm+(0.20mm-0.05mm)-0.03mm strong pressure=25.12mm, so that it can be, if it is strong pressure, it will be about 0.03mm. If the height of the limit column is designed to be 25.15mm, then there is no strong pressure at this time. This is unreasonable. It is best to leave a strong pressure, 0.03mm. For mold parts, please contact DG MF Mold Components Co., Ltd.
★What is the use of continuous die pad?
What is the use of continuous die pad?
The foot can be divided into a lower foot and an upper foot; the plate can be divided into a lower plate and an upper plate.
The main function of the continuous die pad is to support and fix the mold, resist shock absorption, extend the life of the mold, increase the height of the mold, facilitate the frame mold (that is, install the mold on the punching machine), and the lower and lower plates are convenient. Eliminate the role of waste.
What is the use of continuous die pad? In fact, these things are basically useless, you can use them without it because there are mold holders.
In the case of convenient frame mold, the upper plate and the upper foot can be omitted, that is to say, the upper foot and the upper plate are not required, as long as the frame mold is convenient, the frame groove can be designed on the mold base, so that some can be saved. Materials that reduce unnecessary waste and save the company money.
★The role of stamping die
The stripping plate is a common name for the stripping plate. The code for the upper die strip is referred to as the PSU, and the upper plate is the stop plate (PPS), then the plywood (PHU), the backing plate, and the like. Of course, there is not only the upper stripping plate but also the lower stripping plate.
What is off-board? What is the role of stamping die stripping?
The meaning is to remove the material or product from the mold, commonly known as "removing material". When the product is stuck in the mold, it is commonly called "no material". When repairing the mold problem, it often encounters "not taking off". "The problem."
What is the role of stamping die stripping? Of course, the first effect is firstly to remove the product, that is, to remove the product from the mold, and to fit the lower template together.
In combination, there are two functions of the stamping die stripping board. One is to remove the material and the product is unwound; the second one is to press the material for bending, punching and the like.
★ Which parts should be generally included in a relatively complete die?
The components that should be included in a relatively complete die are: template, block, and standard parts;
The template includes: upper and lower pallets, upper and lower pads, upper and lower die, holders, upper and lower templates, upper and lower pads, upper and lower clamping plates, stop baffles, stripping plates, concave molds, punches, also called punches or edges. Wait;
Into the block (upper mold): the splint into the block, the stripping plate into the block, the punch, etc.;
Into the block (lower die): the lower die into the block, the lower die edge, the floating block, the positioning into the sub, etc.;
Standard parts: spring, hexagonal screw, stop screw, wire spring, contour set, guidepost, guide sleeve, ejector sleeve pin, dowel pin, ejector pin, etc.
Non-standard parts: external positioning, internal positioning, pitch positioning, outer limit column, inner limit column, etc.;
★DG MF Mold Components Co., Ltd supplies the general mold parts almost all you need.
