外文翻译--热挤压模具的优化设计-精品Word文件下载.doc

1、 three-dimensional method; modeling; hot extrusion die; optimum designIntroduction With the continuous improvement of living standards, better thermal conductivity of aluminum alloy profiles. Aluminum components widely used in every aspect of life. Therefore, the aluminum alloy extrusion profiles, p

2、rofiles of various types of radiators have been widely used in electrical appliances, machinery, and other industries. Variable products and the growing diversity and complexity of high-precision, the extrusion process is the basis for extrusion die. It not only determines the shape, size, accuracy

3、and surface state, but also affect the performance of the product. So extrusion die extrusion technology is the key. Studies to improve extrusion die quality and prolong its life span usually attempt to simplify 3-D finite element model to 2-D, but it is only right for simple structural shapes. With

4、out a 3-D finite element analysis, the results cannot give practical manufacturing help and offer useful information3-5. In this paper, aluminium profile extrusion die was modeled to get in optimum design6-8.1 Solid Modeling Figure 1 shows the male die of a hot extrusion planar combined die. Its ext

5、ernal diameter is 227.000 mm, its height is 80.000 mm. Other parameters are shown in Fig. 1. The modeling method is as follows.1.1 Coordinates of P1 and P5 The coordinates of the point of intersection between the beeline L （y = kx + b） and the circular arc （x2 + y2 =R2） are 1.2 Coordinates of P2 and

6、 P6 The coordinates of the intersection point （P2） between beeline L1 （y = kx+b） and beeline L2 （y =S1） are The coordinates of the intersection point （P6） between beeline L3 （y = kx+b） and beeline L4 （y =S1） are 1.3 Coordinates of P3, P4, P7, and P8 P3 and P1 are symmetric about the y-axis. P4 and P

7、2 are also symmetric about the y-axis. P7 and P5 are symmetric about the x-axis. P8 and P6 are also symmetricabout the x-axis.1.4 Variables in the equations In Eqs. （1）-（6）, for points P1 and P2, and R = R1. For points P5 and P6, and R = R2. R1, R2, T1, T2, S1, and S2 are the change rule along the h

8、eight （H） of the die expressed as the functions R1=f1 （z）, R2=f2 （z）, T1=f3 （z）, T2=f4 （z）, S1=f5 （z）, andS2=f6 （z）, z 0, H.1.5 Section shape at some height With lines linking P1-P4, P5-P8, with circular arc filleting at the point of intersection （P1-P8）, the section shape at some height is obtained

9、.1.6 Section shape at every height H is divided to interfacial number （INUM） equal parts （INUM is decided by the precision, if the INUM is higher, the precision is better）. The section shape is drawn at every height as shown in Fig. 2. 1.7 Smooth curved surface Using SKIN command in ANSYS, smooth cu

10、rved surfaces were built along the lines. They are the surfaces of the influence hole. Using the VA （it generates a volume bounded by existing area） command, a solid was created from those surfaces.1.8 Symmetry of the die The main body and kernel of the die were drawn using the Boolean operations of

11、 add, subtract, etc. （Fig. 3）.The symmetry of the die was used to accelerate the computations using a 1/4-solid model for the finite element analysis （Fig. 4）.2 Computing Model A planar die that extrudes the aluminium alloy （6063Al-Mg-Si） was used as an example. The liquidoid of Al is 6579, and the

12、melt temperature of Al+Mg2Si is 558. Taking the extrusion pressure and the products quality into account, the working temperature was determined to be 450. The die material is 4Cr5MoSiV1（H13）. Below the 450, its Young modulus and Possion ratio are 210 GPa and 0.25, respectively. Its yield strength i

13、s 1200MPa.The friction coefficient is 0.3. The Solid92 3-D solid element was used to carry through the free mesh. In order to load the frictional force while extruding, the surface effect element Surf154 was used to produce the regular quadrangles （Fig. 5）. For the 1600 t extruder, the extrusion intensity was computed using Eq. （7）10. The values are shown in Table 1. The bridge collapse o