復印機小端蓋注塑模具設計
復印機小端蓋注塑模具設計,復印機,小端蓋,注塑,模具設計
Journal of Mechanical Science and Technology《機械科學與技術雜志》
24 (2010) 145~148
www.springerlink.com/content/1738-494x
DOI 10.1007/s12206-009-1126-5
Optimal injection（最佳注射）molding conditions（成型條件） considering the core shift （型芯的飄動）for a plastic battery case（塑料電池盒）with thin and deep walls（薄壁深腔）?
具有薄壁深腔的塑料電池盒考慮到其型芯的飄動時，最佳注射模型條件。
Dong-Gyu Ahn1,*, Dae-Won Kim2 and Yeol-Ui Yoon3
1Departmentn.（ 部；部門；系；科；局）of Mechanical Engineering, Chosun University （朝鮮大學） , Gwang-Ju, 501-751, Korea（韓國）
2 Incheon Service Division, KITECH, Incheon, 406-840, Korea
3Chun-Bok Injection Mold Inc.（Bok注塑模具有限公司）, Gwang-Ju, 1233-12, Korea
(Manuscript Received April 24, 2009; Revised September 21, 2009; Accepted October 12, 2009)（手稿收到2009年4月24日；2009年9月21日修訂；2009年10月12日接受）
Abstract
摘要
The objective of this paper is to examine the influence of injection molding parameters（<物><數(shù)>參量；參項；決定因素） on the core shift to obtain the optimal （為了獲得最佳）injection molding conditions （注塑條件）of a plastic battery case with thin and deep walls using numerical analyses and experiments（利用數(shù)值分析和實驗）.
這篇文章的目的是利用數(shù)值分析和實驗的方法來檢驗型芯移動時對注射模參數(shù)的影響以及對薄壁深腔塑料電池盒的最佳注塑條件。
Unlike conventional injection molding analysis, the flexible parts(靈活的部件)of the mold were represented（v. 代表；表現(xiàn)；描寫） by 3-D tetrahedron （n. [晶體] 四面體）meshes （n.網(wǎng)孔（ mesh的名詞復數(shù) ）；網(wǎng)狀物；陷阱；困境) to consider the core shift in the numerical analysis.
與傳統(tǒng)的注射成型分析不同，模具的活動部件利用三維四面體網(wǎng)格來表示以數(shù)值分析法來考慮型芯移動。The design of experiments (DOE) was used to estimate(估計，估價；判斷)the proper molding conditions that minimize (vt. 使減到最少；小看，極度輕視vi. 最小化)the core shift and a dominantparameter（一個重要參數(shù)）.
DOE（Design of Experiment）試驗設計，一種安排實驗和分析實驗數(shù)據(jù)的數(shù)理統(tǒng)計方法；試驗設計主要對試驗進行合理安排，以較小的試驗規(guī)模(試驗次數(shù))、較短的試驗周期和較低的試驗成本，獲得理想的試驗結果以及得出科學的結論。
實驗設計(DOE)是用來評估適當?shù)某尚蜅l件下,使型芯移動量最小的一個重要參數(shù)。
The results of the DOE showed that the dominant parameter is the injection pressure, and the core shift decreases when the injection pressure decreases.
結果表明,DOE的主要參數(shù)是注射壓力,當注射壓力降低時型芯移動量也在減小。
In addition, it was shown that the initial mold temperature and the injection time hardly affect the core shift.
此外,研究結果表明,初始模具溫度和注射時間幾乎不影響型芯移動。The results of the experiments showed that products （n. 產(chǎn)品；商品）without warpage （n. [木] 翹曲，彎曲） are manufactured （制造，加工）when the injection pressure is nearly 32 MPa.
實驗的結果表明,當注射壓力接近32 MPa時，制造的產(chǎn)品不發(fā)生彎曲。
Comparing the results of the analyses with those of the experiments, optimal injection molding conditions were determined.
分析的結果與實驗對比,確定了最佳注射成型條件。
In addition, it was shown that the core shift should be considered to simulate（模仿；假裝） the injection molding process of a plastic battery case with thin and deep walls.
此外,結果表明,模擬注塑一個塑料電池盒薄壁深腔的工藝應考慮型芯移動。
Keywords: Optimal injection molding condition; Core shift; Thin and deep walls; Battery case; Design of experiments .關鍵詞:優(yōu)化注塑條件;型芯飄動;薄和深墻;薄壁深腔;試驗設計。
1.
Introduction One of the recent（adj. 最近的；近代的） concerns（關系；關心；企業(yè)）in the automotive industry （汽車工業(yè)）is the reduction of overall weight to improve fuel（燃料） efficiency（效率） and reduce a vehicle’s(車輛) environmental impact [1-3].
介紹最近汽車行業(yè)中人們普遍關心的問題之一是用減小車輛整體重量來提高燃油效率以及減少車輛對環(huán)境產(chǎn)生影響[1 - 3]。
The injection molding process of thinner plastic components allows considerable weight savings on the automotive（汽車）, a significant（顯著） reduction in production cost, and a shorter cycle time [1].
薄塑料部件注射成型工藝性可以較大的減小汽車的重量，大幅度降低生產(chǎn)成本和縮短生產(chǎn)周期[1]。
Various studies （各種研究）are actively undertaken in an effort to develop the injection molding process of thin-wall plastic parts [1].
人們都在積極努力的從事各項研究來開發(fā)薄壁塑料件的注塑模工藝[1]。
High injection pressure and high injection speed are necessary to manufacture（制造）plastic parts with thin and deep walls [4].制造生產(chǎn)薄壁深腔的塑料零件必須要使用高噴射壓力和高噴射速度[4]。
However, a high injection pressure can give rise（導致） to a core shift,which is the spatial（空間） deviation（偏差） of the position of the core during injection molding [5].
然而,一個高噴射壓力能增加一個型芯移動,這是型芯在注塑中空間位置的偏差形成的[5]。
Shepard et al. found that the mold design and injection molding conditions strongly affect the core shift of the mold [6].
Shepard 等人發(fā)現(xiàn)在模具設計和注塑條件強烈影響型芯移動[6]。
Leo et al. reported that the deflection （n. 偏向；撓曲；偏差）of weak（弱） plates (板塊）in the mold causes variations in the thickness (厚度)of the product and the over-packing (過度)of moldings (n. 模型制品；線腳)[7].
Leo 等人報道,模具中強度較差的模板的彎曲會使產(chǎn)品的厚度發(fā)生變化[7]。
Bakharev et al. reported that core shift effects in injection molding can be predicted through mold filling simulation coupled with an elastic analysis （彈性分析）of the flexible parts of the mold [4].
Bakharev等人報道,可以通過模具填充模擬和易變形模具的零件的彈性分析可事先知道注塑成型時型芯移動的作用情況[4]。
In this paper, the influence of injection molding parameters on the core shift in the injection molding of a plastic battery case with thin and deep walls is examined to estimate an optimal injection molding condition.
本文對注射成型參數(shù)影響具有薄壁深腔的塑料電池盒考慮到其型芯的飄動時，來評估最佳注射模型條件。
The design of experiments is used to estimate a proper molding condition minimizing the core shift, as well as to determine a dominant molding parameter.
實驗設計是用來評估最小化型芯偏移時適當?shù)某尚蜅l件,以及確定主要成型參數(shù)。
Several experiments are carried out to obtain an optimal injection pressure.
多次進行了試驗研究用來獲得一個理想的噴射壓力。
Comparing the results of numerical analyses with those of the experiments, the optimal injection molding condition is acquired.
最優(yōu)注塑條件是通過對實驗結果進行數(shù)值分析對比獲得的。
The effects of the core shift on the quality of the product are also discussed.
探討研究型芯偏移對產(chǎn)品的質(zhì)量的影響。
2.
2。
Numerical analysis and experiments In order to simulate the core shift and injection molding characteristics （n. 特性，特征；特色（characteristic的復數(shù)）；特質(zhì)）, a three-dimensional injection molding analysis was performed using the commercial code MPI V6.1.
實驗和數(shù)值分析來模擬型芯偏移的注射成型特點,一個三維的注射成型進行了分析使用MPI V6.1.。
Fig. 1 illustrates the analysis model.
圖1模型分析說明。
The dimensions of the battery case are 164.4 mm (W) × 251.4 mm (L) × 184.0 mm (H). The maximum and minimum thicknesses of the walls are 2.7 mm and 1.8 mm, respectively.
電池盒的尺寸是164.4毫米(W)×251.4毫米(L)×184.0毫米(H),最大和最小厚度的薄壁分別是2.7毫米和1.8毫米。
The depth of the walls is 168.7 mm. The runner system （澆注系統(tǒng)）consists of a conical sprue with an initial diameter of 8 mm and a final diameter of 15 mm, circular runners(圓形通道) with diameters of 8 mm, and pin-point gates（澆口） with diameters of 2 mm. In order to consider the core shift phenomenon （現(xiàn)象）in the numerical analysis, the flexible parts of the mold and the flow part were represented by 376,674 EA of tetrahedron meshes and 61,098 EA of shell meshes（殼網(wǎng)格）, respectively.深腔的深度為168.7毫米。澆注系統(tǒng)由一個錐形澆道（初始直徑8毫米和最后直徑15毫米）,圓形通道的直徑8毫米,澆口直徑在2毫米。為了考慮型芯移動現(xiàn)象的數(shù)值分析,動模的模具和活動部件分別用四面體網(wǎng)格376674 EA和61098 EA殼網(wǎng)格代表。
The injection material was a polypropylene resin（聚丙烯樹脂）.注射材料是聚丙烯樹脂。
The melting temperature of PP was set at 230 oC.
聚丙烯融化溫度設定在230 oC。
The design of experiments (DOE) was used to quantitatively （數(shù)量上；分量上）examine the influence of injection molding parameters on the core shift.
實驗設計(DOE)用來定量檢查型芯移動對注塑參數(shù)的影響。
Table 1 shows the injection molding parameters and their levels for the L9 (34) orthogonal array.
表1顯示了注塑參數(shù)的水平幅附圖用繪(34)正交陣列表示。
The signalto-noise (S/N) ratio with the-smaller-the-better characteristics was calculated to estimate the proper condition for minimizing the core shift.
信噪比(S / N)的特點是用計算估算優(yōu)的條件下最小型芯移動。
The contribution（n. 貢獻；捐獻；投稿）ratio of each parameter（每個參數(shù)） is estimated using Analysis of Variance (ANOVA) to obtain the dominant parameter affecting the core shift.
用每個參數(shù)的貢獻比率來估算使用方差分析(ANOVA)獲得型芯移動的主要參數(shù)影響。
Several experiments were performed（執(zhí)行） using an injection molding machine with 600 tons of clamping force.
注射成型機用600噸的夾緊力進行幾個實驗。
Fig. 2 shows the design of the mold, as well as the manufactured mold, for the experiments.
圖2顯示了模具的設計,以及模具的制造,實驗。
The dimensions of the mold are 750 mm (W) × 700 mm (L) × 870 mm (H). The dominant parameter was varied within ± 10 % of the proposed condition by the DOE to determine the optimal condition.
模具的尺寸為750毫米×700毫米(W)(L)×870毫米(H)。主要參數(shù)變化在±10%的由DOE提出條件來確定最佳條件。
In order to examine the influence of core shift on the simulation of the injection molding process, the results of the experiments are compared to those of the numerical analyses.為了檢驗型芯移動在模擬注塑工藝中的影響,實驗結果用數(shù)值分析進行比較。
3.
Results and discussion
討論與結果
3.1 Results of injection molding analysis and DOE Fig. 3 and Table 2 show the results of the injection molding analysis.
3.1 DOE的注射成型結果分析圖3和表2注塑分析顯示結果。
The flexible parts of the core were deformed （變形）in identical directions（方向） regardless of the combination of injection molding conditions, as shown in Fig. 3.
在任何注塑條件的組合下動模的型芯的變形方向相同,見圖3。
Fig. 3 and Table 2 show that the deformations of the F1, F5, and F6 parts of the core were greater than 0.1 mm and flexible parts of the core deformed symmetrically.
圖3和表2表明,變形的F1,F5、F6部分的型芯是大于0.1毫米和動模型芯變形對稱。
In addition, it was noted that the shifts of the F2 and F3 parts are negligible in comparison with those of other parts.
此外,他們注意到F2和F3變化的部分相比,是可以忽略不計的其他部分。
From the results of the injection molding analysis, the S/N and contribution ratios were calculated for the F1, F5, and F6 parts of the core with relatively large core shifts.
從結果的注塑成型分析、S / N和貢獻比率計算的F1,F5、F6部分的型芯與相對較大的型芯偏移。
Fig. 4 and Table 3 show the results of the DOE.
圖4和表3DOE顯示結果。
In Fig. 4, it can be seen that the S/N ratios of the injection pressure, the holding time, the injection time, and the initial mold temperature are maximized (最大化)when their values (n. 價值觀念；價值標準)are 30 MPa, 1.6 seconds, 4.4 seconds, and 40 oC, respectively.
圖4中,可以看到,S / N比率的噴射壓力、保溫時間、注射時間、初始模具溫度是最大的時候,他們的標準分別是是30 MPa,1.6秒,4.4秒,40攝氏度。
The S/N ratio of the in jection pressure also increases remarkably （adv. 顯著地；非常地；引人注目地） when the injection pressure decreases, as shown in Fig. 4.
當注射壓力降低S / N比率在注射壓力也增加明顯,見圖4。
Table 3 shows that the mean value of the contribution ratio of the injection pressure is nearly 76.3 % and that the contribution ratio of the injection pressure is markedly higher than that of the other parameters.
表3顯示,平均比例的噴射壓力是近76.3%,在比率中的噴射壓力明顯高于其他參數(shù)。
From these results, it was noted that the dominant parameter, which mainly affects the core shift, is the injection pressure.從這些結果,指出主要參數(shù),主要影響型芯偏移的,就是注射壓力。
The variation in ratio and the contribution ratio for the injection time and the initial mold temperature are negligible, as shown in Fig. 4 and Table 3.
不同的S/N 注射時間和初始模具溫度都可以忽略不計,見圖4和表3。From these results, it was noted that the injection time and the initial mold temperature hardly affect the core shift.從這些結果,指出注射時間和初始模具溫度幾乎沒有影響到型芯偏移。
3.2 Results of the experiments Using the results of the DOE, the experimental conditions of injection time, holding time, and initial mold temperature were set at 1.6 seconds, 4.4 seconds, and 40 oC, respectively.
3.2 DOE實驗結果使用結果,實驗條件的注射時間、保溫時間、初始模具溫度分別設定在1.6秒,4.4秒,40攝氏度。
The injection pressure was varied in the range of 27-32 MPa.注射壓力變化范圍在27 - 32 MPa。
Fig. 5 shows the results of the injection molding experiments.圖5顯示了注射成型的實驗結果。
The shortshot did not occur in all experimental conditions, as shown in Fig. 5.
在所有的實驗條件中不包括短時間注射,如圖5所示。
However, the warpages of the walls of the molded product occurred when the injection pressure was lower than 30 MPa, as shown in Fig.
當然,在注射壓力低于30 MPa不能制作薄壁易變形的模制產(chǎn)品,見圖5(a)。
This results from the insufficient（不足）holding pressure.
這是保持壓力不足的結果。
The warpages of the product walls do not occur when the injection pressure is 32 MPa, as shown in Fig. 5(b).
當注射壓力是32 MPa時薄壁易變形的產(chǎn)品也不能生產(chǎn),見圖5(b)。
From these results, the optimal injection molding conditions of the tested plastic battery case with thin and deep walls were determined as an injection pressure of 32 MPa, an injection time of 1.6 seconds, a holding time of 4.4 seconds, and an initial mold temperature of 40 oC.
從這些結果,塑料電池盒的薄壁深腔優(yōu)化注塑條件的測試被確定為注射壓力32 MPa、注射時間1.6秒,保持時間4.4秒,初始模具溫度為40攝氏度。
The results of the experiments were compared to those of the numerical analyses, as shown in Fig. 6.
實驗的結果進行了數(shù)值分析比較,見圖6。
Fig. 6(a) shows that the difference in wall thickness between the analyses and the experiments is reduced from -0.15 mm ~ 0.18 mm to -0.09 mm ~ 0.07 mm when the core shift is considered in the numerical analysis.
圖6(a)表明,在壁厚之間的差異分析的實驗是減少從-0.15 mm ~ 0.18毫米到-0.09毫米~ 0.07毫米當型芯偏移被認為是在數(shù)值分析。
In addition, it was noted that the thickness variation of the walls is properly predicted by the core shift analysis.
此外,它是指出,厚度變化的深腔是正確預測的型芯偏移分析。
Fig. 6(b) shows that the core shift appreciably affects the post-deformation pattern of the molded product, and the numerical analysis accounting for the core shift can predict the post-deformation of the product within 0.15 mm of computational accuracy.
圖6(b)表明,偏芯偏移略微影響變形期后的模制產(chǎn)品模式,數(shù)值分析會計為核心轉變可以預測產(chǎn)品的變形期后在0.15毫米的計算精度。
The results of the numerical analyses show that the injection pressure is reduced from 50.2 MPa to 32.0 MPa when the core shift is considered.
數(shù)值分析的結果表明,當型芯偏移被認為是從注射壓力降低到32.0 MPa從50.2 MPa。
This is due to increased cavity volume induced by the elastic deformation of the core.
這是由于增加了空腔體積引起的彈性變形的型芯。
Based on the above results, it is noted that injection molding analysis accounting for（對…負有責任；對…做出解釋；說明……的原因）the core shift can properly simulate the injection molding process of the battery case with thin and deep walls.
基于上述結果,型芯偏移注塑分析可以正確地模擬電池外殼的薄壁深腔注塑工藝。
4.
Conclusions ，The influence of injection molding parameters on the core shift in the molding of a plastic battery case with thin and deep walls was investigated using numerical analysis and the experiment.
結論， 注射成型對型芯偏移成型的塑料電池盒薄壁深腔的影響參數(shù)采用了實驗和數(shù)值分析。
The elastic deformation of the core was considered to reflect core shift effects on the numerical analysis.
彈性變形的型芯被認為是反映型芯偏移影響數(shù)值分析。
Through numerical analysis and DOE, it was shown that the injection pressure is the dominant process parameter affecting core shift and that the core shift decreases when the injection pressure decreases.
通過數(shù)值分析和DOE顯示注射壓力是主要過程參數(shù)影響型芯偏移,當注射壓力降低時型芯偏移減小。
In addition, it was noted that the injection time, the holding time, and the initial mold temperature hardly affect core shift.此外,它是指出,注射時間、保壓時間、初始模具溫度幾乎沒有影響型芯偏移。
It was demonstrated through experiments that the molded product without warpages can be manufactured at an injection pressure of approximately 32 MPa.
通過實驗證明,一個注射壓力約為32 MPa是不可以制造較厚壁厚模制產(chǎn)品。
Comparing the results of the numerical analyses with those of the experiments, the optimal injection molding conditions were obtained.
比較結果的數(shù)值分析與實驗,獲得了最佳注塑條件。
In addition, it was shown that the core shift should be considered to accurately simulate the injection molding process of a plastic battery case with thin and deep walls.此外,結果表明,型芯偏移應該準確地模擬一個塑料電池盒薄壁深腔注塑工藝。
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Dong-Gyu Ahn received his B.S. degreein Production and Mechanical Engineering from Pusan National University,Korea, in 1992. He then received his M.S. and Ph.D. degrees from KAIST in 1994 and 2002, respectively. Dr. Ahn is currently a Professor at the Department of Mechanical Engineering at Chosun University in Gwang-Ju, Korea. Dr. Ahn’s research interests include rapid prototyping and manufacturing（快速原型設計制造）, lightweight sandwich panel（輕質(zhì)夾板）, laser material processing, and molds and dies.
Ahn1992年在韓國釜山國立大學獲得機械工程學士學位。他1994年和2002年在KAIST(韓國科學技術院 )又分別獲得了碩士和博士學位。Ahn博士目前任韓國光州的朝鮮大學機械工程系教授。Ahn博士的研究興趣包括快速原型設計制造，輕質(zhì)夾板，激光材料加工，及模具。
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