鋅合金壓鑄成品之模流分析

Molding Analysis for Die-Casting of Zinc Alloys

黃啟源(Chi-Yuan Huang)

指導教授 ： 鍾文仁

中原大學/工學院/機械工程研究所/碩士(2004年)

https://doi.org/10.6840/cycu200400065

摘要

摘要
本研究以鋅合金為原料，應用壓鑄法來探討金屬拉鏈中之拉片元件的成型過程；首先用模流分析軟體ProCASTTM模擬鋅合金在模穴中的充填情形，以預測鑄件充填時可能產生的缺陷，並再以實際之生產設備所得之產品作印證分析與比較，以期得到模具最佳化之澆口、流道及溢料區。
在分析的三個案例中分別以對稱模穴、單邊模穴與可能具包風情形來設計模型進行模擬討論，並對有問題之模型診斷出改善方案，來尋求解決之道。第一個案例中，主要針對形狀變化大與表面上含有0.25mm之凸起部，利用分析軟體觀察其流體之波前與流動狀態；在模擬與實際射出比對後，其流動波前相當的一致，且發現充填完成後有一溢料區為不必要的，因此在模具設計時此部分可以省略，相對的也將減少加工時間。第二個案例主要針對單邊模穴作設定，由於生產數量之因素有時會使用單邊模生產，因此才對此模型作分析；在實際射出與分析軟體的波前與充填狀況比較下，也非常吻合。第三個案例主要在探討包風現象，由於此模型在實際射出與充填過程中，當流體接觸到標誌(logo)處流動變慢，而使邊緣之流體的波前超前，以致造成包風狀況。針對第三個案例的問題，本文提出三種改善方案，來尋求解決之道；在不厭其煩地模擬分析與診斷結果下發現，案例三之最佳改善方式，可將溢料區加大，讓包風位置之氣體在流動液體的推動力，將其移入溢料區來解決此包風現象。

關鍵字

壓鑄 ； ProCASTTM ； 鋅合金

並列摘要

Abstract
This paper utilized the material of zinc-alloy with using casting method to investigate the forming process of pulling-slice which is a part of metallic zipper. The filling processes of zinc-alloy were simulated by using ProCAST software in molding cavity and the potential drawbacks would be predicted under the filling procedure, and then taking advantage of the realistic experiment in the factory we made some product to prove the validity of simulated analyses in terms of ProCAST software. Comparing with computational simulation and experimental test about the filling situation in molding cavity, these resultants would be able to acquire the perfect filling procedures including gate, runner and material overflowing area.
Three molding procedures including symmetrical molding cavities, unilateral molding cavity and cavity containing air traps were designed to simulate the filling circumstance. According to the analytic resultant of computational simulation and experimental test, these molding would be diagnosed their defects and proposed schemes of improvement. First case, where utilizing symmetrical molding cavities, would mainly probe the flow front of the part which the shape of surface is vast variety and has a salient of thickness 0.25mm on the surface using ProCAST software. The resultant of computational simulation corresponded with practical experiment on the flowing front and some overflowing area may be neglected under original design about the molding cavity. For some realistic demand in the industry, second case focused the flowing front of zinc-alloy on unilateral molding cavity. The resultant of computational simulation also agreed with practical experiment on the flowing front. The last case focused on phenomenon of air traps in the molding cavity. Due to the practical injection and filling melted process with the model, the flow rate slowed down when it flowed and touched the salient logotype of part. The flowing fluid without the flowing front of salient logotype would lead and form air traps in the molding cavity. In this paper, three reforming strategies of air traps were adopted to obtain the performance for the third case. These reformed molds were patiently found and diagnosed an optimal proposal of improvement which is to enlarge the overflowing area, so that gas in the situation of air traps could be removed and went into the enlarged overflowing area depending on the impetus of flowing fluid.

並列關鍵字

ProCAST software ； Zinc-alloy ； casting method

參考文獻

2. “Zine Alloy Die Casting,” JIS standard H5301.

4. R. W. Bruner, “The Metallurgy of Die Casting,” Society of Die Casting, 1986.

9. ProcastTM user’s manual & technical reference ,appendix C.

考文獻

1. 唐乃光 主編，壓鑄模具設計手冊，初版，金屬工業研究發展中心，民國87年6月