1、Stamping and Punching DiesCompound Die Design A compound die performs only cutting operations (usually blanking and piercing) which are completed during a single press stroke. A characteristic of compound dies is the inverted position of the blanking die and blanking punch which also functions as th
2、e piercing die. The die is fastened to the upper shoe and the blanking punch having a tapered hole in it and in the lower shoe for slug disposal is mounted on the lower shoe. The guide pins, or posts, are mounted in the lower shoes. The upper shoes contains bushing which slide on the guide pins. The
3、 assembly of the lower and upper shoes with guide pins and bushing is a die set. Die sets in many sizes and designs are commercially available. On the upstroke of the press slide, the knock out rod of the press strikes the ejector plate, forcing the ejector tie rod and shedder downward, thus pushing
4、 the finished work piece out of the blanking die. Four special shoulder screws (stripper bolts), commercially available, guide the stripper in its travel and retain it against the preload of its springs. The blanking die as well as the punch pad is screwed and doweled to the upper shoe. 1、 Bending D
5、ie Bending is the uniform straining of material, usually flat sheet or strip metal, around a straight axis which lies in the neutral plane and normal to the lengthwise direction of the sheet or strip. Metal flow takes place within the plastic range of the lengthwise direction of the bend retains a p
6、ermanent set after removal of the applied stress. The inner surface of a bend is in compression; the outer surface is in tension. A pure bending action does not reproduce the exact shape of the punch and die in the metal; such a reproduction is one of forming. The neutral axis is the plane area in b
7、end metal where all strain is zero. 2、 Bending Methods Metal sheet or strip, supported by a V bending, produces a bend having an included angle which may be acute, obtuse, or of 90. Friction between a spring-loaded knurled pin in the Vee of a die and the part will prevent or reduce side creep of the
8、 part during its bending. Other methods are Z-bending edge bending and U-bending etc. 3、 Drawing Die Drawing is a process of changing a flat, precut metal blank into a hollow vessel without excessive wrinkling, thinning, or fracturing. The various forms produced may be cylindrical or box-shaped with
9、 straight or tapered sides or sides or a combination of straight, tapered, or curved sides. The size of the parts may vary from 0.25mm diameter or smaller, to aircraft or automotive parts large enough to require the use of mechanical handing equipment. 4、 Single-action Die The simplest type of draw
10、dies is one with only a punch and die. One type of drawing die use in a single-action press is shown in Fig.3-4. This die is plain single-action type where the punch pushes the metal blank into the die, using a spring-loaded pressure pad to control the metal flow. The punch has an air vent to elimin
11、ate suction which would hold the cup on the punch and damage the cup when it is stripped from the punch by the pressure pad. The sketch shows the pressure pad fitting the stop pin, which acts as a spacer that an even and proper pressure is exerted on the blank at all times. If the spring pressure pa
12、d is used without the stop pin, the more the springs are depressed, the greater the pressure exerted on the blank, thereby limiting the depth of drawing. Because of limited pressures obtainable, this type of die should be used with light- gage stock and shallow depths. Mold Cavities and Cores The ca
13、vity and core give the molding its external shapes respectively, the impression imparting the whole of the form to the molding. When then proceeded to indicate alternative ways by which the cavity and core could be incorporated into the mold and we found that these alternatives fell under two main h
14、eadings, namely the integer method and the insert method. Another method by which the cavity can be incorporated is by means of split inserts or splits. When the cavity or core is machined from a large plate or block of steel, or is cast in one piece, and used without bolstering as one of the mold p
15、lates, it is termed an integer cavity plate or integer core plate. This design is preferred for single-impression molds because of characteristics of the strength, smaller size and lower cost. It is not used as much for multi-impression molds as there are other factors such as alignment which must b
16、e taken into consideration. Of the many manufacturing processes available for preparing molds only two are normally used in this case. There are a direct machining operation on a rough steel forging or blank using the conventional machine tool, or the precision investment casting technique in which
17、a master pattern is made of the cavity and core. The pattern is then used to prepare a casting of the cavit y or core by or special process. A 4.25% nickel-chrome-molybdenum steel (BS 970-835 M30) is normally specified for integer mold plates which are to be made by the direct machini ng method. The
18、 precision investment casting method usually utilizes a high-chrome steel. For molds containing intricate impressions, and for multi-impression molds, it is not satisfactory to attempt to machine the cavity and core plates from single blocks of steel as with integer molds. The machining sequences an
19、d operation would be altogether too complicated and costly. The inset-bolster assembly method is therefore used instead. The method consists in machining the impression out of small blocks of steel. These small blocks of steel are known, after machining, as inserts, and the one which forms the male
20、part is termed the core insert and, conversely, the one which forms the female part the cavity inserts. These are then inserted and securely fitted into holes in a substantial block or plate of steel called a bolster. These holes are either sunk part way or are machined right through the bolster pla
21、te. In the latter case there will be a plate fastened behind the bolster and this secures the insert in posit ion. Both the integer and the insert-bolster methods have their advantages depending upon the size, the shape of the molding, the complexity of the mold, whether the single impression or a m
22、ulti-impression mold is desire, the cost of making the mold, etc. It can therefore be said that in general, once the characteristics of the mold required to do a particular job which have been weighed up, the decision as to which design to adopt can be made. Some of these considerations have already
23、 been discussed under various broad headings, such as cost, but to enable the reader to weigh them up more easily, when faced with a particular problem, the comparison of the relative advantages of each system is discussed under a number of headings. Unquestionably, for single impression molds integ
24、er design is to be preferred irrespective of whether the component form is a simple or a complex one. The resulting mold will be stronger, smaller, less costly, and generally incorporate a less elaborate cooling system than the insert -bolster design. It should be borne in mind that local inserts ca
25、n be judiciously used to simplify the general manufacture of the mold impression. For multi-impression molds the choice is not so clear-cut. In the majority of cases the insert-bolster method of construction is used, the ease of manufacture, mold alignment, and resulting lower mold costs being he ov
26、erriding factors affecting the choice. For components of very simple form it is often advantageous to use one design for one of the mold plate and the alternative design for the other. For example, consider a multi-impression mold for a box-type component. The cavity plate could be of the integer de
27、sign to gain the advantages of strength, thereby allowing a smaller mold plate, while the core plate could be of insert-bolster design which will simplify machining of the plate and allow for adjustments for mold alignment.1 Die position in industrial productionMold is a high-volume products with th
28、e shape tool, is the main process of industrial production equipment. 采用模具生产零部件，具有生产效率高、质量好、成本低、节约能源和原材料等一系列优点，用模具生产制件所具备的高精度、高复杂程度、高一致性、高生产率和低消耗，是其他加工制造方法所不能比 With mold components, with high efficiency, good quality, low cost, saving energy and raw materials and a series of advantages, with the mol
29、d workpieces possess high accuracy, high complexity, high consistency, high productivity and low consumption , other manufacturing methods can not match. 已成为当代工业生产的重要手段和工艺发展方向。 Have already become an important means of industrial production and technological development. 现代经济的基础工The basis of the mod
30、ern industrial economy. 现代工业品的发展和技术水平的提高，很大程度上取决于模具工业的发展水平，因此模具工业对国民经济和社会发展将起越来越大的作用。The development of modern industrial and technological level depends largely on the level of industrial development die, so die industry to national economic and social development will play an increasing role. 1989
31、 年 3 月国务院颁布的关于当前产业政策要点的决定中，把模具列为机械工业技术改造序列的第一位、生产和基本建设序列的第二位 ( 仅次于大型发电设备及相应的输变电设备 ) ，确立模具工业在国民经济中的重要地位。 March 1989 the State Council promulgated on the current industrial policy decision points in the mold as the machinery industry transformation sequence of the first, production and capital constru
32、ction of the second sequence (after the large-scale power generation equipment and the corresponding power transmission equipment), establish tooling industry in an important position in the national economy. 1997 年以来，又相继把模具及其加工技术和设备列入了当前国家重点鼓励发展的产业、产品和技术目录和鼓励外商投资产业目录。 Since 1997, they have to mold
33、and its processing technology and equipment included in the current national focus on encouraging the development of industries, products and technologies catalog and to encourage foreign investment industry directory. 经国务院批准，从 1997 年到 2000 年，对 80 多家国有专业模具厂实行增值税返还 70% 的优惠政策，以扶植模具工业的发展。 Approved by t
34、he State Council, from 1997 to 2000, more than 80 professional mold factory owned 70% VAT refund of preferential policies to support mold industry. 所有这些，都充分体现了国务院和国家有关部门对发展模具工业的重视和支持。 All these have fully demonstrated the development of the State Council and state departments tooling industry attent
35、ion and support. 目前全世界模具年产值约为 600 亿美元，日、美等工业发达国家的模具工业产值已超过机床工业，从 1997 年开始，我国模具工业产值也超过了机床工业产值。 Mold around the world about the current annual output of 60 billion U.S. dollars, Japan, the United States and other industrialized countries die of industrial output value of more than machine tool industr
36、y, beginning in 1997, Chinas industrial output value has exceeded the mold machine tool industry output.据统计，在家电、玩具等轻工行业，近 90 的零件是综筷具生产的；在飞机、汽车、农机和无线电行业，这个比例也超过 60 。According to statistics, home appliances, toys and other light industries, nearly 90% of the parts are integrated with production of cho
37、psticks; in aircraft, automobiles, agricultural machinery and radio industries, the proportion exceeded 60%. 例如飞机制造业，某型战斗机模具使用量超过三万套，其中主机八千套、发动机二千套、辅机二万套。 Such as aircraft manufacturing, the use of a certain type of fighter dies more than 30,000 units, of which the host 8000 sets, 2000 sets of engin
38、es, auxiliary 20 000 sets. 从产值看， 80 年代以来，美、日等工业发达国家模具行业的产值已超过机床行业，并又有继续增长的趋势。 From the output of view, since the 80s, the United States, Japan and other industrialized countries die industry output value has exceeded the machine tool industry, and there are still rising. 据国际生产技术协会预测，到 2000 年，产品尽件粗加工
39、的 75% 、精加工的 50 将由模具完成；金属、塑料、陶瓷、橡胶、建材等工业制品大部分将由模具完成， 50 以上的金属板材、 80 以上的塑料都特通过模具转化成制品。 Production technology, according to the International Association predicts that in 2000, the product best pieces of rough 75%, 50% will be finished mold completed; metals, plastics, ceramics, rubber, building materi
40、als and other industrial products, most of the mold will be completed in more than 50% metal plates, more than 80% of all plastic products, especially through the mold into.模具的历史发展 2 The historical development of mold模具的出现可以追溯到几千年前的陶器和青铜器铸造，但其大规模使用却是随着现代工业的掘起而发展起来的。The emergence of mold can be trace
41、d back thousands of years ago, pottery and bronze foundry, but the large-scale use is with the rise of modern industry and developed.19 世纪，随着军火工业 ( 枪炮的弹壳 ) 、钟表工业、无线电工业的发展，冲模得到广泛使用。The 19th century, with the arms industry (guns shell), watch industry, radio industry, dies are widely used. 二次大战后，随着世界经
42、济的飞速发展，它又成了大量生产家用电器、汽车、电子仪器、照相机、钟表等零件的最佳方式。 After World War II, with the rapid development of world economy, it became a mass production of household appliances, automobiles, electronic equipment, cameras, watches and other parts the best way. 从世界范围看，当时美国的冲压技术走在前列许多模具先进技术，如简易模具、高效率模具、高寿命模具和冲压自动化技术，大
43、多起源于美国；而瑞士的精冲、德国的冷挤压技术，苏联对塑性加工的研究也处于世界先进行列。 From a global perspective, when the United States in the forefront of stamping technology - many die of advanced technologies, such as simple mold, high efficiency, mold, die and stamping the high life automation, mostly originated in the United States; an
44、d Switzerland, fine blanking, cold in Germany extrusion technology, plastic processing of the Soviet Union are at the world advanced. 50 年代，模具行业工作重点是根据订户的要求，制作能满足产品要求的模具。 50s, mold industry focus is based on subscriber demand, production can meet the product requirements of the mold. 模具设计多凭经验，参考已有图纸
45、和感性认识，对所设计模具零件的机能缺乏真切了解。 Multi-die design rule of thumb, reference has been drawing and perceptual knowledge, on the design of mold parts of a lack of real understanding of function. 从 1955 年到 1965 年，是压力加工的探索和开发时代对模具主要零部件的机能和受力状态进行了数学分桥，并把这些知识不断应用于现场实际，使得冲压技术在各方面有飞跃的发展。 From 1955 to 1965, is the pre
46、ssure processing of exploration and development of the times - the main components of the mold and the stress state of the function of a mathematical sub-bridge, and to continue to apply to on-site practical knowledge to make stamping technology in all aspects of a leap in development. 其结果是归纳出模具设计原则
47、并使得压力机械、冲压材料、加工方法、梅具结构、模具材料、模具制造方法、自动化装置等领域面貌一新，并向实用化的方向推进，从而使冲压加工从仪能生产优良产品的第一阶段。 The result is summarized mold design principles, and makes the pressure machine, stamping materials, processing methods, plum with a structure, mold materials, mold manufacturing method, the field of automation device
48、s, a new look to the practical direction of advance, so that pressing processing apparatus capable of producing quality products from the first stage.进入 70 年代向高速化、启动化、精密化、安全化发展的第二阶段。Into the 70s to high speed, launch technology, precision, security, development of the second stage. 在这个过程中不断涌现各种高效率、商
49、寿命、高精度助多功能自动校具。 Continue to emerge in this process a variety of high efficiency, business life, high-precision multi-functional automatic school to help with. 其代表是多达别多个工位的级进模和十几个工位的多工位传递模。 Represented by the number of working places as much as other progressive die and dozens of multi-station transfer station module. 在此基础上又发展出既有连续冲压工位又有多滑块成形工位的压力机弯曲机。 On this basis, has developed both a continuous pressing station there are more slide forming station of the press - bending machine. 在此期间，日本站到了世界最前列其模具加工精度进入了微米级，模具寿命，合金工具钢制造的模具达到了几千万次，硬质合金钢制造的模具
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