STAMPING AND SHEET METAL FORMI

1、STAMPING AND SHEET METAL FORMING沖壓成形和板材沖壓【中英文對照】STAMPING AND SHEET METAL FORMINGStamping is a kind of plastic forming process in which a part is produced by means of the plastic forming the material under the action of a die，stamping is usually carried out under cold state, so it is also called stam

2、ping, heat stamping is used only when the blank thickness is greater than 8-100mm.the blank material for stamping is usually in the form of sheet or strip, and therefore is it also called sheet metal forming. Some non-metal sheets (such as plywood. Mica sheet, asbestos. Leather can be formed by stam

3、ping.Stamping is widely used in various fields of the metalworking industry. And it plays a crucial role in the industries for manufacturing automobiles. Instruments. Military parts and household electrical appliances. EtcThe process, equipment and die are the three foundational problems that needed

4、 to be studied in stamping.The characteristics of the sheet metal forming are as follows;high material utilizationcapacity to produce thin-walled parts of complex shapeGood interchangeability stamping pares due to precision in shape and dimension.Parts with lightweight. High-strength and fine rigidi

5、ty can be obtained.High productivity. Easy to operate and to realize mechanization and autoimmunization.The manufacturer of the stamping die is costly. And there pore it only fits to mass production for the manufacture of products in small batch and rich variety. The simple stamping die and the new

6、equipment such as a stamping nothing center are usually adopted to meet the market demands.The materials for sheet metal stamping include mild steel. Copper, Aluminum, Magnesium alloy and high-plasticity alloy-steel, etc.Stamping equipment includes plate shear punching press. The former shears plate

7、 into strips with a definite width, which would be pressed later, the later be used both in shearing and forming.2, characteristics of stamping formingThree are various processes of stamping forming with different working patterns and names. But these processes are similar to each other in plastic d

8、eformation. These are following conspicuous characteristics in stamping;The force per unit area perpendicular to the blank surface is not large but is enough to cause the material plastic deformation it is much less than the inner stresses on the plate plane directions. In most cases stamping formin

9、g can be treated approximately as that of the plane stress state to simplify vastly the theoretical analysis and calculation of process parameters.Due to the small relative thickness, the anti-instability capability of the blank is weak under compressive stress. As a result, the stamping process is

10、difficult to proceed successfully without using the anti-instability device; therefore the varieties of the stamping processes dominated by tensile are more than dominated by compressive stress.During stamping forming the inner stress of the blank is equal toor sometimes less than the yield stress o

11、f the material in this point, the stamping is different from the bulk forming, during stamping forming, the influence of the hydrostatic pressure of the stress state in the bulk forming. In some circumstances, such influence may be neglected. Even in the case when this influence should be considered

12、, the treating method is also different from that of bulk forming.In stamping forming. The restrain action of the die blank is not severs as in the case of the bulk forming, in bulk forming. The constraint forming is preceded by the die exactly the same shape of the part. Whereas in stamping. In mos

13、t cases. The blank has a certain degree of freedom. Only one surface of the blank contacts with the die. In some extra cases, such as the forming of the blank on the deforming zone contact the die.The deformation in these regions is and controlled by the die applying an external force to its adjacen

14、t area.Due to the characteristics of stamping deformation and mechanics mentioned stamping technique is different form the bulk metal forming;The importance or the strength and the rigidity of die in stamping forming that in bulk forming because can be formed without applying large area on its surfa

15、ce. Instead. The simple die and the pneumatic forming are developed.Due to the plane stress or simple strain state in comparison with research on deformation or force and power parameters has been done, stamping forming can be performed by more reasonable scientific methods, based on the real time a

16、nalysis on the sheet metal and stamping parameters by means of modern testing apparatus. Research on the intellectualized control of stamping proceedingIt is shown that there is a close between stamping materials. The research on the properties of the stamping forming, that is, shape stability on th

17、e properties of the forming that is, shape stability, has because a key point in stamping technology development, the technique of iron and steel industry, and provides a increasing sheet metal quality.3. CATEGORIES OF STAMPING FORMINGMany deformation processes can be done by stamping, the basic pro

18、cesses can be divided into two kinds, cutting and forming.Cutting is a shearing process that one part of the blank is cut form the other. It mainly includes blanking, punching, trimming, parting and shaving, where punching and blanking are the most widely used. Forming is a process that of the blank

19、 has some displacement form the other. It mainly includes deep drawing, bending, local forming, Bulging, flanging necking, sizing and spinning.In substance, stamping forming is such that the plastic deformation occurs in the deformation zone of stamping blank caused by the external force. The stress

20、 state and deformation characteristic of the deformation zone are the basic factors to decide the properties of the stamping forming. Based on the stress state and deformation characteristics of the deformation zone, the forming methods網(wǎng)can divided into several categories with the same forming prope

21、rties and be studied systematically.The deformation zone in almost all of stamping forming is in the plane stress state. Usually there is no force or only small force applied on the blank surface. When is assumed that the stress perpendicular to the blank surface equals to zero, two principal stress

22、es perpendicular to each other and act on the blank surface, the stress state and the deformation characteristics of the deformation of stamping forming can be denoted by the points in the coordinates of the plane principal stresses and the coordinates of the corresponding plane principal stains4. R

23、AW MATERIALS FOR STAMPING FORMINGThere are a lot of raw materials used in stamping forming and the properties of these materials may have large difference. The stamping forming can be succeeded only by determining the stamping method, the forming the relationships between the material properties for

24、 stamping forming is as follows;Definition of stamping property of the material.Method to judge the stamping property of the material, find parameters to express the definitely material property of the stamping forming. Establish the relationship between the property parameters and the practical sta

25、mping forming. And investigate the methods of the property paramters.Establish the materials for stamping forming mainly include various metals and nonmetal plate. Sheet metal includes both ferrous and nonferrous metals. The most widely used materials are steel, stainless steel, aluminum alloy and v

26、arious composite metal plates5. STAMPING FORMING PROPERTY OF SHEET METAL AND ITS ASSESSING METHODThere are direct and indirect testing methods to assess the stamping property of the sheet metal.Practicality stamping test the most direct method to assess stamping forming property of the sheet meals.

27、This test is done exactly in the same condition as actual production by using the practical and dies. Surely, this test result is most reliable. But this kind of assessing method is not comprehensively applicable. And cannot be shared as a commonly used standard between factories.The simulation test is a kind of assessing method that after simplifying and summing up actual stamping forming methods, as well as eliminating trivial factors, the stamping properties of the sheet metal are assessed. Base