外文翻譯--儀表板注塑成型過程仿真系統(tǒng)的建立（英文）

1、The Establishment of the Instrument Panel Injection Molding Process Simulation System Wang Cuiping School of Transportation and Vehicle Engineering Shandong University of Technology Zibo P.R. China 255049 e-mail:

2、 wangcuiping@126.com Abstract—in this paper, we establish the simulation system of a car dashboard injection molding process simulation in software MOLDFLOW based on the fundamental issues involved in the injection mo

3、lding process, and established several analysis programs for the simulation of injection molding the instrument panel, and laid the foundation for optimization. Keywords-instrument panel; injection molding; simulatio

4、n system I. INTRODUCTION Now the market competition becomes more and more intensive, the product upgrade frequently, the companies must respond quickly in order to improve competitiveness. In order to improve the

5、competitiveness of automotive products in the market, the car designers must reduce the automobile components design cycle, improve design quality and reduce the cumulative error brought about by the data transformat

6、ion in the design process, reduce development costs. Now the applications of computer-aided design in the process of the automobile becomes more extensive, the computer-aided design technologies such as three- di

7、mensional data measured, data processing, surface reconstruction, three-dimensional modeling and rapid manufacturing, and other related technologies can be easily applied in the design of the car body, the car body ri

8、gidity, the mold manufacturing of the automobile components, thus the vehicle development cycle can be greatly reduced. the application of plastic parts on the car have been gradually increased, there are various qua

9、lity defects and abnormal phenomena in the injection molding production process, for a long time, most of the workers handle the situation by the experience only, so the blind transfer machine cost a long time and th

10、e raw material waste a lot. The injection Molding is a knowledgeable and highly technical industry, during machine the experience alone is not enough, the technical personnel must aware and understand the performance

11、 of polymer materials, processing, molding, mold design, injection molding machinery considerably, so high demands are placed on the technology staff. For mold designers and product manufacturers, the forecast and se

12、ttlement the potential shortcomings of plastic components can improve and enhance the product quality, shorten the product development cycles, reduce the production costs [1]. II. THE FEATURES OF THE INSTRUMENT PANEL

13、 The structure of the instrument panel is complex, the wall is thinner, the size is large, the injection mold is large, the elastic deformation of the mold is large, so the injection process is easy to produce the phe

14、nomenon of excess material. The gating system and the cavity volume is large, in which accumulating a lot of air, so it is very ease to generate the defects such as cavitation, over-burning, etc. The injection moldin

15、g process is long, the wall is thin, so it is easy to generate non-uniform molecular orientation, cooling properly, resulting in the warping and distortion of the products. The injection volume is very large, when the

16、 melt shrink during cooling and solidifying, it tends to have depression and sink marks. If an injection molding using a whole system, the injection process of the instrument panel require materials with good mobili

17、ty, flame resistance, high rigidity and hardness, low shrinkage and high impact strength. Currently, the materials of PPO, ABS resin, filled PP are widely used in the car instrument panel, In addition, the magnesium a

18、lloy casting also occupy a certain market. The thickness of the instrument panel wall we used is 3.5mm, which is favourable for eliminating or reducing the internal stress, preventing the molded products to deform a

19、nd crack. III. THE ESTABLISHMENT OF THE SIMULATION SYSTEM IN MOLDFLOW A. pre-processing 1) importing the 3D model into moldflow First, export the three-dimensional graphics drawn by UG in * igs format, then create a

20、 new project in the Moldflow, and import the * igs format graphics into Moldflow, set the average thickness as 3.5mm. the imported graphics is shown as figure1. 2) mesh generation The mesh in moldflow is classified

21、as midplane, fusion, and 3D. Due to the instrument panel is the large thin-walled injection, the mesh of the instrument panel is generated with midplane model. After the *.igs file is imported, we can generate the me

22、sh of the instrument panel, the side length of element is the default value 55.1940mm, the combined tolerances if the igs is 0.01mm. ___________________________________ 978-1-61284-240-0/11/$26.00 ©2011 IEEE 205T

23、he design of the running system is not only directly affecting the intrinsic quality of products and apparent quality, geometric condition, physical and mechanical properties, but also relate to the ease of the mold f

24、illing and the flow state filling as mold filling, and whether it is easily separated with the products. So for the mold design, the design of the right gating system is critical. Because the hot runner (Hot Runner)

25、can reduce waste, shorten cycle times, and improve product accuracy, this simulation adopts the hot runner system or the system combined with hot and cold runner. 1) the selection of the gate type The selection of t

26、he gate can influence the product performance, shape, size, quality, greatly, and has the close relation with the utilization of the resin and the production forming. So the selection of the gate is the most importan

27、t issue in the design of the injection mold. The gate types are divided into four major categories: sprue gate, common gate, submarine gate and pin gate. Because the cross-section dimension of the pin gate is very sm

28、all, so it has many advantages and is widely used. In this simulation we use the pin gate. 2) Cold Slug Well The cold slug well is usually located in the main channel or in the end of a corner of the primary shunt.

29、Its role is to clog the cold material from the molding machine nozzle, to prevent the material from entering the parts, to ensure a smooth filling and get the high quality parts. The cross- section of the cold slug we

30、ll is generally trapezium. 3) the size of the Runner Systems The runner system plays a dual role of mass and heat transfer, and thus the rheological behavior of plastic melt is the concerned core. Because the runner

31、systems are various in forms, the structures are complex and the flow of the plastic melt in the system was non-Newtonian fluid, so we use the polymer melt rheology theory to determine the size of the runner system.

32、a) the sprue section size [2]. The shear rate of the non-Newtonian fluid is 3 1 n Qn R ? ?? ? ? ???? The ?? is the shear rate of the plastic melt flow, 1 s? ; ? Q- Plastic melt volume flow rate, 3 / cm s , determined

33、 by the volume of plastic parts and injection time. ? n- the melt Non-Newtonian index, related with the melt temperature and shear rate. ? R- the radius of circular flow channel. The experiment shows that the mel

34、t flow shear rate in the sprue takes as 3 1 5 1 0 s ? ? ? ? ? , inserting the value in formula 1, we can calculate the formula2 . 13 3 1 0.08 ( ) s n d Q n? ? ???? ? s d - the diameter of circular flow channel. After c

35、alculating, the volume of the instrument panel and the runner system is 1210 3 cm . In accordance with the past experience in similar product development, we take initially the injection time as 3.0s. so the Plastic

36、melt volume flow rate Q is about 404 3 / cm s , when the temperature is 240 , according the polymer power law table we can determine the n=0.26, inserting the n in the formula 2, calculate the following : 13 3 0.26 1

37、0.08 ( 404) 1.2 0.26 s d cm ? ? ? ? ? ?The section shape of the sprue is conical, so the diameter of the small end section is 8mm; the diameter of the big end section is 12mm. b) the subchannel section size According

38、the function of the sunchannel and the requirement of the little pressure drop and the little heat dissipation, we take the shear rate as 2 1 5 10 s ? ? ? ? ?when the plastic melt flow in the subchannel. Inserting the

39、 value in the formula 1, we can get the following formula3 : 13 3 1 0.172( ) r r n d Q n? ???? ?? r d - the diameter of the subchannel. ? Qr- Plastic melt volume flow rate in subchannel in the formula, the value of

40、Qr is 202 3 / cm s , take n as 0.3. Inserting the numbers in the formula 3, we can get the following: 1 3 3 0 .3 0 1 0 .1 7 2 ( 2 0 2 ) 1 .1( ) 0 .3 0 r d c m ? ? ? ? ? ?so we take the diameter of the subchannel secti

41、on as 10mm. c) the gate section size The shear rate of the melt flow in the small end of the sprue gate is 4 1 5 10 s ? ? ? ? ? , inserting the value in formula 1 can get the following: 13 3 1 0.037( ) G G n d Q n? ?

42、?????? G d -the diameter of the small end of the sprue gate. ? G Q -Plastic melt volume flow rate through the gate. 3 0.5 202 / G Q Q cm s ? ?13 3 0.13 1 0.037 ( 202) 0.48( ) 0.13 G d cm ? ? ? ? ? ?so the diameter of t

43、he small end section of the sprue gate is 5mm, the diameter of the big end section of the sprue gate is 8mm. in the pin gate, the shear rate of the melt flow is 5 1 10 s ? ? ? ? , inserting the value in the formula