支撐板冷沖壓工藝及級進(jìn)模設(shè)計
支撐板冷沖壓工藝及級進(jìn)模設(shè)計,支撐,沖壓,工藝,級進(jìn)模,設(shè)計
英文原文
Die Life of cold stamping die and influence
Die with the life of the workpiece by punching out the number of terms. Many factors affect the life Die. There are die structure design, manufacture molds used in the punch and die materials, die quality and surface hardening heat treatment, precision die manufacturing parts and cold stamping materials selection. In addition, there are die installation, adjustment, use and maintenance.
1. Die Design on Life
(1) Layout design of layout methods and take the boundary value a great impact on the die life, too small to take the boundary value, often causing rapid wear and convex mold, die bite wounds on the. Starting from material savings, take the boundary value smaller the better, but take the edge is less than some value, the cut surface of the mold and the quality of life adversely. There will be left behind in the blanking die Q-gap were to produce spare parts glitch, or even damage the die edge, reduce die life. Therefore, consider increasing the material utilization of the same time, parts must yield, quality and life expectancy to determine the layout methods and take the boundary.
(2) die structure prone to stress concentration on the cracking of the die structure, composite structure can be used or mosaic structure, and prestressed structure to enhance the mold life.
(3) the impact of clearance when the gap is too small, compressed extrusion of interest, increased friction, increased wear, the wear side of aggravated discharge and push pieces after blanking time, materials and convex, the friction between die will cause wear and tear than the end edge on the side of the grinding much, but also easily lead to convex, concave mold temperature is high, the adsorption of metal debris in the side edge to form a metal tumor, so that male and female die chipping or expansion occurs crack phenomenon. Therefore, the gap is too small to Die Life very bad. Gap is too large will increase the punch and the die face the edge of the concentration of stress, resulting in a sharp increase in stress, so blade edge quickly lose angular yield deformation. Therefore, addition of blanking force, thereby enabling faster edge edge wear, reduce die life. But in order to reduce the male and female die wear, extending mold life, while ensuring quality of stamping pieces under the premise that larger space designed properly it is necessary.
(4) Die-oriented structure of the life of a reliable guide for the working parts reduce wear, prevent male and female die bite wound is very effective. In particular, non-small-Q gap Q gap or Die, compound die and multi-position progressive die even more important. To improve the die life, must be based on processes and the demand of precision, the correct choice-oriented form and orientation accuracy, the choice should be higher than the accuracy-oriented convex, concave mold with precision.
(5) the impact of cold stamping materials, cold stamping materials selected should meet the design requirements of workpieces and stamping process requirements, or easy to mold damage and reduce mold life. Poor surface quality of cold stamping, punching, cracking when the workpiece is also easy to scratch mold. Bad cold stamping plastic materials, deformation is small, easy to press when the workpiece rupture, but also easy to scratch mold. In addition, the material thickness tolerances shall comply with national standards. Die because of a certain thickness of material suitable for forming, bending, flanging, drawing die of the male and female die structure gap is directly determined by the thickness of the material. Therefore, uneven thickness, will result in waste generation and mold damage.
2. Die Die Life of
Die Die Life of a mold material properties, chemical composition, structure, hardness and comprehensive reflection of metallurgical quality. Among them, the material properties and heat treatment affect the quality of the most obvious. Mold material properties on the impact of die life is great. If the same workpiece, using a different mold material of the bending test, the test results: The 9Mn2V material, the life of 5 million; with Crl2MoV nitriding, the life of up to 40 million. Therefore, the choice of materials, the batch size should be based on workpiece, rational use of mold materials. The hardness of the die parts to Die Life a great impact. But not the higher hardness, longer die life. This is because the hardness and strength, toughness and abrasion resistance are closely related. Some die demands of high hardness, long life. Such as the use of T10 steel dies, hardness 54 ~ 58HRC, only washed thousands of times a burr on the workpiece great. If the hardness to 60 ~ 64HRC, the grinding life of up to 2 to 3 million. However, if continue to improve hardness, fracture occurs earlier. Some die hardness should not be too high, as the die manufacturing using Crl2MoV 58 ~ 62HRC hardness, the general life of 2-3 million, invalid form of chipping and cracking, and if the hardness down to 54 ~ 58HRC, life expectancy increased to 5 ~ 60 000, but decreased to 50 ~ 53HRC hardness appears easy to blunt the die edge phenomenon. Thus, mold hardness must be based on material properties and failure modes may be. Should enable the hardness, strength, toughness and wear resistance, resistance to fatigue strength needed to achieve a particular stamping process the best match.
3. The surface of the mold heat treatment to strengthen the quality and impact on life
Mold heat treatment the nature and quality of life of the mold a great impact. Practice shows that the die parts of the quenching distortion and cracking, early fracture during use, while the metallurgical and materials quality, forging quality, mold structure and process related, but related more to die of heat treatment. According to statistical analysis of failure causes of mold, heat treatment failure due to improper accounting for more than 50%. Practice shows that the mold material must be accompanied by high heat treatment process properly, can really play a material's potential. Parts surface hardening mold work purpose is to obtain the effect of external hard tough inside, so be hardness, wear resistance, toughness, good resistance to fatigue with. Many ways to die surface hardening, surface treatment technology of new technologies developed rapidly. In addition to Nitrocarburizing and ion nitride, boride, seepage niobium, vanadium permeability, hard chrome plated and spark strengthening, the chemical vapor deposition (CVD) and physical vapor deposition (PVD) has been gradually adopted. By CVD and PVD treatment, the mold surface covered with super-hard material, such as TiC, TiN, etc.. High hardness, wear resistance, corrosion resistance, adhesion is very good, can improve the die life several times to several times.
4. Manufacturing precision of the die parts of die life
Precision die manufacturing and life in it in particular, mold surface roughness on the mold a great impact. If using Crl2MoV steel blanking die, if the surface roughness value R = 1.6 m, its life span is about 30,000. Such as polished by the precision, surface roughness value R = 0.4 m, life can be increased to 4-5 million. Therefore, the working parts of the mold surface, the general must go through grinding, grinding, polishing and other finishing and fine processing.
5. Other aspects of the impact of die life
(1) Press the accuracy is not high, but also easy to make die damage.
(2) die in the press or not installed properly and the operator's technical level, on the tool life is also greatly affected.
(3) dies in the custody and maintenance of good and bad, and the use of lubricant condition also affects mold life.
Cold stamping mould convex, concave die size and distribution of the clearance degree directly affect the quality of the blanking pieces and the length of the service life of the die. In guarantee blanking pieces space is mould manufacturing assembly very important link, and assembly quality will directly influence the convex, concave die if the clearance between the uniform. Such as the process of convex, concave die size precision although already meet the requirements, but in assembling if adjustment is bad, can cause clearance does not even, rushed out of the spare parts of the raw edges. Even rushed out of unqualified parts. The mold assembly is key to control convex, concave die of relative positions, in order to ensure that the convex, concave die, uniform and the clearance between the right to rush out of qualified parts.
1. Die before assembly the problems that should be paid attention[2]
Convex, concave die and mould parts itself is clearance of the precision, and the assembly of the assembly process is reasonable. In order to ensure that the position of the convex, concave die correctly and gaps even, mould design, processing to assembly from the whole link should pay attention to the following questions：
（1）Convex, concave die design and manufacture of the right
Design should be based on the above all when die cutting the section of a quality, service life of die factors such as the reasonable selection of convex, concave die clearance. And to consider the mould in the process of using that gap wear increases, general in the design the least reasonable clearance when mould. And in the manufacturing process can ensure the parts processing precision and quality, in the assembly process ensure convex, concave die gap even, this for processing complex shape is very key parts.
（2）Assembly method the choice should be reasonable
Die assembly method include roughly assembly method and direct with assembly method. Before the assembly must be carefully study mold assembly drawing, full consideration and analysis of the structure characteristics of punching die, die parts processing technology and processing accuracy etc, in order to choose convenient, accurate and reliable assembly method to ensure the quality of blanking pieces.
2. Convex, concave die gap between the control and adjustment of the method[3]
Convex, concave die clearance control, should according to die structure, clearance size, blanking pieces of quality and practical assembly condition to selected. Convex, concave die gap between the control and adjustment method have the following kinds.
（1）Pervious to light method
Will convex, concave die after molmerged, shone a light on the underside, observe the convex, concave die around through light and distribution to judge the size of the clearance and uniformity. If not even, to adjust to evenly between fixed again, this method is suitable for small gap plate stamping die.
（2）Feeler method
Will convex, concave die after molmerged, convex, concave die into the thickness of unilateral clearance feeler convex, concave die gaps in each direction. Then tighten the screw on mode. Finally put paper to stamping and will last mould seat and fixed on board with drilling, reaming positioning pin hole, and at a pin location.
（3）Gaskets DiaoZhengFa
Gasket adjustment method is simple, convenient, clearance is used widely. As shown in figure 1 shows, the mat with good contour mat iron, will gaskets wrapped in the punch to the punch into the concave mould, observe the convex, concave die clearance condition. If clearance does not even, with striking the protruding models of fixed plate method clearance adjustment, then tighten the screw on mode. Finally put paper to stamping, observation on paper cutting around burr and even rate to judge whether clearance convex, concave die even, to adjust the gap until cutting burr uniform so far. Finally the mould seat and the plate with drilling, reaming positioning pin hole, and enter the pin location. This method widely used cutting materials focusing thick large clearance and bending stamping, deep drawing mould clearance control.
(4) Chemical method
When the convex, concave die complex shape, the use of the above several methods more difficult to adjust the gap, the chemical method can be used to control the gap, the plating method is used. Plating method is the punch in the work surface coated with copper or zinc instead of washers. The plating thickness and unilateral gap is same, blade people concave die hole, and check the move without block phenomenon can assembly tighten. Coating in use process will die fall off naturally, need not removed. This uniform coating, can improve the uniformity of assembling clearance.
(5) Technology DiaoZhengFa measures
The main technological measures to adjust the gap between two kinds of the mould method:
1. Size method
Processing of the punch, will the punch front-end appropriate lengthen, extended period of section size and sunken model hole processing to the same size. Assembly, make the punch into female model hole, natural form the cutting clearance, and then to the punch with fixed together with the punch mould seat on board with the pin for fixed and will last longer period of the punch front can remove form even clearance.
2. Positioning hole method
Process positioning hole method and the inside of the progressive die principle about. Processing, the punch in fixed board and concave die on the same position processing two positioning hole, can will locate hole and the mold cavity a cut out. Assembly, in the positioning hole insert pins to ensure that gap.
(6) Standard model method
According to the drawing wedm in advance in processing a standard model or the qualified stamping parts, to adjust the assembly put it in between convex, concave die, upper and lower die relative motion can be reasonable degree when appropriate.
(7) Measurement method
Measuring method of the measuring tool have feeler. A feeler method after the adjustment convex, concave die clearance good uniformity, it is the commonly used method. Assembly, the punch in the concave die in the hole, convex, concave die according to the size of the clearance choose different specifications of the feeler insert convex, concave die clearance, inspection concave die around the blade gap everywhere, and according to the measured results adjustment. If the adjustment of the punch fixed board knock until adjust good so far.
(8) Adjustment method of repair match means
Die in use after period of time, because the convex, concave die normal wear and tear. To working parts inspection, if products produce burr, convex, concave die dull and collapse the blade factors, it is because of the convex, concave die clearance for wear changed, namely bigger or not even. To make the convex, concave die restored to the original gap value out of parts can use the following method to qualified for repair match means.
1. Convex, concave die clearance greaten repair match means method
General dies in use after period of time, because normal wear will make convex, concave die gap increase gradually, thus to make the work and so on a series of problems produced burr. This kind of circumstance, can use first thickness is equal to one of the KuaiGui insert gap between the convex, concave die, if convex, concave die clearance does not too big, the grinding work part of the blade continue to use, can improve the quality of stamping. When gap value too big when, the recoverable high temperature heat of local forging the modification methods female die size make it restored to the original gap value. Workpiece cooling followed by the pressure seal the law to file to trim gap value, and with the flame hardening method to improve the blade surface hardness.
2. Convex, concave die clearance does not even repair match means method
Dies after a period of using, clearance does not even can make blunt a local produce burr or the blade was edge chewed. In normal wear punching die, because after wearing precision guide device that reduce convex, concave die happen relatively migration, respectively in the guide pin and a guide to cover on the plating chromium layer the restored to its original size, again through the pressure seal the law will remove file high. If it is due to the pins loosening lose positioning function and cause different convex, concave die heart, and cause convex, concave die clearance does not even. Should first will convex, concave die gap adjusting well, to match for taper pin.
Due to historical reasons for the formation of closed, "big and complete" enterprise features, most enterprises in China are equipped with mold workshop, in factory matching status since the late 70s have a mold the concept of industrialization and specialization of production. 生產(chǎn)效率不高，經(jīng)濟(jì)效益較差。 Production efficiency is not high, poor economic returns. 模具行業(yè)的生產(chǎn)小而散亂，跨行業(yè)、投資密集，專業(yè)化、商品化和技術(shù)管理水平都比較低。 Mold production industry is small and scattered, cross-industry, capital-intensive, professional, commercial and technical management level are relatively low.
據(jù)不完全統(tǒng)計，全國現(xiàn)有模具專業(yè)生產(chǎn)廠、產(chǎn)品廠配套的模具車間（分廠）近17000家，約60萬從業(yè)人員，年模具總產(chǎn)值達(dá)200億元人民幣。 According to incomplete statistics, there are now specialized in manufacturing mold, the product supporting mold factory workshop (factory) near 17 000, about 600 000 employees, annual output value reached 20 billion yuan mold. 但是，我國模具工業(yè)現(xiàn)有能力只能滿足需求量的60％左右，還不能適應(yīng)國民經(jīng)濟(jì)發(fā)展的需要。 However, the existing capacity of the mold and die industry can only meet the demand of 60%, still can not meet the needs of national economic development. 目前，國內(nèi)需要的大型、精密、復(fù)雜和長壽命的模具還主要依靠進(jìn)口。 At present, the domestic needs of large, sophisticated, complex and long life of the mold also rely mainly on imports. 據(jù)海關(guān)統(tǒng)計，1997年進(jìn)口模具價值6.3億美元，這還不包括隨設(shè)備一起進(jìn)口的模具；1997年出口模具僅為7800萬美元。 According to customs statistics, in 1997 630 million U.S. dollars worth of imports mold, not including the import of mold together with the equipment; in 1997 only 78 million U.S. dollars export mold. 目前我國模具工業(yè)的技術(shù)水平和制造能力，是我國國民經(jīng)濟(jì)建設(shè)中的薄弱環(huán)節(jié)和制約經(jīng)濟(jì)持續(xù)發(fā)展的瓶頸。 At present the technological level of China Die & Mould Industry and manufacturing capacity, China's national economy in the weak links and bottlenecks constraining sustainable economic development.
1、模具工業(yè)產(chǎn)品結(jié)構(gòu)的現(xiàn)狀 1. Research on the Structure of industrial products mold
按照中國模具工業(yè)協(xié)會的劃分，我國模具基本分為10大類，其中，沖壓模和塑料成型模兩大類占主要部分。 In accordance with the division of China Mould Industry Association, China mold is divided into 10 basic categories, which, stamping die and plastic molding two categories accounted for the main part. 按產(chǎn)值計算，目前我國沖壓模占50％左右，塑料成形模約占20％，拉絲模（工具）約占10％，而世界上發(fā)達(dá)工業(yè)國家和地區(qū)的塑料成形模比例一般占全部模具產(chǎn)值的40％以上。 Calculated by output, present, China accounts for about 50% die stamping, plastic molding die about 20%, Wire Drawing Die (Tool) about 10% of the world's advanced industrial countries and regions, the proportion of plastic forming die die general of the total output value 40%.
我國沖壓模大多為簡單模、單工序模和符合模等，精沖模，精密多工位級進(jìn)模還為數(shù)不多，模具平均壽命不足100萬次，模具最高壽命達(dá)到1億次以上，精度達(dá)到3～5um，有50個以上的級進(jìn)工位，與國際上最高模具壽命6億次，平均模具壽命5000萬次相比，處于80年代中期國際先進(jìn)水平。 Most of our stamping die mold for the simple, single-process mode and meet the molds, precision die, precision multi-position progressive die is also one of the few, die less than 100 million times the average life of the mold reached 100 million times the maximum life of more than accuracy 3 ~ 5um, more than 50 progressive station, and the international life of the die 600 million times the highest average life of the die 50 million times compared to the mid 80s at the international advanced level.
我國的塑料成形模具設(shè)計，制作技術(shù)起步較晚，整體水平還較低。 China's plastic molding mold design, production technology started relatively late, the overall level of low. 目前單型腔，簡單型腔的模具達(dá)70％以上，仍占主導(dǎo)地位。 Currently a single cavity, a simple mold cavity 70%, and still dominant. 一模多腔精密復(fù)雜的塑料注射模，多色塑料注射模已經(jīng)能初步設(shè)計和制造。A sophisticated multi-cavity mold plastic injection mold, plastic injection mold has been able to multi-color preliminary design and manufacturing. 模具平均壽命約為80萬次左右，主要差距是模具零件變形大、溢邊毛刺大、表面質(zhì)量差、模具型腔沖蝕和腐蝕嚴(yán)重、模具排氣不暢和型腔易損等，注射模精度已達(dá)到5um以下，最高壽命已突破2000萬次，型腔數(shù)量已超過100腔，達(dá)到了80年代中期至90
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