1、 1 毕 业 设 计 （ 论 文 ） 英 文 翻 译 课题名称 系 部 材 料 工 程 系 专 业 材料成型及控制工程 班 级 KT633-01 学 号 2006K330130 姓 名 指导教师 2 0 10 年 3 月 10 日 2 4 Sheet metal forming and blanking 4.1 Principles of die manufacture 4.1.1 Classification of dies In metalforming,the geometry of the workpiece is established entirely or partially b
2、y the geometry of the die.In contrast to machining processes,ignificantly greater forces are necessary in forming.Due to the complexity of the parts,forming is often not carried out in a single operation.Depending on the geometry of the part,production is carried out in several operational steps via
3、 one or several production processes such as forming or blanking.One operation can also include several processes simultaneously(cf.Sect.2.1.4). During the design phase,the necessary manufacturing methods as well as the sequence and number of production steps are established in a processing plan(Fig
4、.4.1.1).In this plan,the availability of machines,the planned production volumes of the part and other boundary conditions are taken into account. The aim is to minimize the number of dies to be used while keeping up a high level of operational reliability.The parts are greatly simplified right from
5、 their design stage by close collaboration between the Part Design and Production Departments in order to enable several forming and related blanking processes to be carried out in one forming station. Obviously,the more operations which are integrated into a single die,the more complex the structur
6、e of the die becomes.The consequences are higher costs,a decrease in output and a lower reliability. Fig.4.1.1 Production steps for the manufacture of an oil sump 3 Types of dies The type of die and the closely related transportation of the part between dies is determined in accordance with the form
7、ing procedure,the size of the part in question and the production volume of parts to be produced. The production of large sheet metal parts is carried out almost exclusively using single sets of dies.Typical parts can be found in automotive manufacture,the domestic appliance industry and radiator pr
8、oduction.Suitable transfer systems,for example vacuum suction systems,allow the installation of double-action dies in a sufficiently large mounting area.In this way,for example,the right and left doors of a car can be formed jointly in one working stroke(cf.Fig.4.4.34). Large size single dies are in
9、stalled in large presses.The transportation of the parts from one forming station to another is carried out mechanically.In a press line with single presses installed one behind the other,feeders or robots can be used(cf.Fig.4.4.20 to 4.4.22),whilst in large-panel transfer presses,systems equipped w
10、ith gripper rails(cf.Fig.4.4.29)or crossbar suction systems(cf.Fig.4.4.34)are used to transfer the parts. Transfer dies are used for the production of high volumes of smaller and medium size parts(Fig.4.1.2).They consist of several single dies,which are mounted on a common base plate.The sheet metal
11、 is fed through mostly in blank form and also transported individually from die to die.If this part transportation is automated,the press is called a transfer press.The largest transfer dies are used together with single dies in large-panel transfer presses(cf.Fig.4.4.32). In progressive dies,also k
12、nown as progressive blanking dies,sheet metal parts are blanked in several stages；generally speaking no actual forming operation takes place.The sheet metal is fed from a coil or in the form of metal strips.Using an appropriate arrangement of the blanks within the available width of the sheet metal,an optimal material usage is ensured(cf.Fig.4.5.2 to 4.5.5). The workpiece remains fixed to the strip skeleton up until the la
