厚板差溫引伸與縮口成形製程之研究

The Study of Deep Drawing and Sinking Processing for the Thick Plate on Thermal Differential

劉政優(Cheng-You Liu 劉政優)

指導教授 ： 許源泉

國立虎尾科技大學/工程學院/創意工程與精密科技研究所/碩士(2010年)

摘要

本研究主要探討差溫引伸與縮口製程，首先針對AISI-1045板材進行材料性質分析，以建立塑流應力曲線及異向性指數，並結合田口方法與套裝軟體DEFORM-3D進行製程參數最佳化設計；包含沖頭圓角、母模圓角、沖頭斜角及模具間隙等模具幾何外型的探討，然後利用得到的最佳製程參數，透過VISI沖模設計軟體與模具設計理論進行模具設計；另一方面利用有限元素模擬厚板差溫引伸與縮口成形製程分析，探討胚料成形溫度、摩擦因子及沖頭速度等成形參數 對引伸及縮口件負荷、應變的影響。
研究發現，透過拉伸試驗結合應變規與網格蝕刻能建立AISI-1045板材資料庫，對於實驗與模擬上能更加趨近吻合；在模具幾何外型最佳化設計上，引伸時沖頭圓角3 mm、母模圓角10 mm及模具間隙1.1t，能得到最佳的引伸厚度，而在縮口時沖頭入口圓角3 mm、沖頭入口斜角45°及沖縮口行程11 mm能得到最佳縮口孔徑。
在探討成形溫度、沖頭速度及摩擦因子等參數中，發現差溫引伸成形溫度及沖頭速度越高，可相對降低引伸負荷；而摩擦因子大小對負荷則有增大的趨勢。差溫引伸成形溫度越高、沖頭速度越快，則能有效減少引伸圓筒圓隅處之應變，進而減緩圓隅處厚度變薄；而在差溫縮口中成形溫度及沖頭速度越高，亦可相對降低縮口負荷，摩擦因子大小對負荷則有增大的趨勢，且在縮口的等效應變則是成形溫度越高，等效應變降低；沖頭速度則沒多大影響，摩擦則是會增加等效應變。
另外在實驗部分主要進行引伸件成形，來驗證模擬與設計的可行性，從實驗中發現成形溫度在700℃引伸出的圓筒會產生破裂；而模擬則是可成形，最主要為加熱設備無法達到像模擬所設定的溫度梯度。

關鍵字

差溫引伸 ； 差溫縮口 ； 田口方法 ； 最佳化設計

並列摘要

The current study aims to investigate the thermal differential deep drawing and sinking process. Firstly, an approach based on the mechanical properties of an AISI-1045 was applied to construct flow stress curve and the anisotropy index. Then, the Taguchi method and DEFORM-3D finite element method were combined to conduct the optimization design of process parameters, which included the die profile parameters such as punch radius, die radius, punch angle and die clearance. Based on those optimal process parameters, the VISI die design commercial code and die design theory were used for the die design. Furthermore, in order to explore the influence of blank forming temperature, friction factor, and punch speed forming parameters on the forming load and the strain in the deep drawing and sinking parts, the finite element software was employed to simulate the thermal differential deep drawing and sinking forming process.
Study showed that the tensile test combining with strain gauge and grid etching could establish AISI-1045 stamping database, and enhance better agreement between the experiment and the simulation results. As for the die geometry optimization design, the best deep drawing thickness could be attained when the deep drawing punch radius is 3 mm, die radius 10 mm and die clearance 1.1 t. And when the sinking process punch entrance radius is 3 mm, punch entrance bevel 45°, and sinking stroke 11 mm, the best necking aperture could be generated.
Through the investigation of other parameters, such as the forming temperature, punch speed, and the friction factor, it was found that higher temperature and punch speed in thermal differential drawing process can relatively lower the drawing load, and the friction factor size for the load has the enlargement tendency. When the thermal differential deep drawing forming temperature and punch speed are higher, the strain at the deep drawing cylinder round corner is effectively reduced, further slowing down the thinning of the round corner. In addition, when the forming temperature and punch speed are higher in the thermal differential sinking, the sinking load can be relatively reduced, and the friction factor size of the load increases. The effective strain at sinking is slower when the forming temperature is higher. The punch speed has not much influence on the effective strain, and friction will increase the effective strain.
As for the experiment, deep drawings are performed to verify the feasibility of simulation and design. The experimental results showed that the cylindrical drawn cup derived at the forming temperature of 700 ℃ will appear rupture; forming by simulation is possible, mainly because the temperature gradient set up by simulation could not be reached by the heating equipment.

並列關鍵字

thermal differential deep drawing ； thermal differential sinking ； Taguchi method ； design of optimization

參考文獻

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