陶瓷雷射快速原型機之鋪層系統改善

Improvement of Layer Paving System in Ceramic Laser Rapid Prototyping Machine

林大吉(Da-Gi Lin)

指導教授 ： 湯華興 ； 嚴孝全

國立臺北科技大學/機電學院/機電整合研究所/碩士(2010年)

摘要

本實驗室之陶瓷雷射快速原型設備分為三部分，包括鋪層系統、雷射掃描系統及控制系統。現有之鋪層系統有以下缺點：(1)鋪層時會和懸臂升降機構產生共振，導致生薄層產生波紋，使層厚不均勻，層與層間無法確實黏結。(2)使用螺旋泵做為供料機構時其螺桿常囤積漿料，且螺距過大難以控制精準的供料量。此外，在鋪層時水份會下滲到生坯塊內，鋪層厚度與水份下滲深度成正比增加，當下滲深度超過臨界飽和厚度(Critical Saturated Thickness, CST)便會產生裂痕。
本文之目的為設計一個新式的鋪層系統，包含升降機構、鋪料機構及供料機構，來改善上述之缺點。運用楔型原理，設計一個精密度高且性能良好的新式升降機構，在總行程510μm層厚30μm，定位精度誤差-16μm、重覆精度28.4μm以內，達到振動幅度縮小為0.76μm，以避免鋪層時之共振現象。設計新式供料機構，改善使用上的不便，亦能精準控制供料流量，使漿料在運用上更為經濟。並運用改善後的鋪層系統，在無裂痕的先決條件下，增加鋪料速度或縮小層厚可以使水分下滲減少。

關鍵字

快速原型 ； 鋪層 ； 升降機構 ； 供料

並列摘要

The existing ceramic laser rapid prototyping apparatus in our laboratory includes three systems which are layer casting system, laser scanning system and control system. Current apparatus has drawbacks as following: (1) the overhanging elevating mechanism vibrated during layer casting; such phenomenon leads to a ripple layer, uneven layer thickness, and weak binding between the layers. (2) the slurry feeding mechanism uses screw pump; however, the screw shaft always stocks up a lot of slurry and screw pitch is too large to precisely control the slurry feeding. Besides, water will infiltrate to the green block during the layer casting and the infiltrating depth is proportional to the layer thickness. When the infiltrating depth is greater than the critical saturated thickness (CST), cracks will occur on the surface of the layer.
For improving the aforementioned shortcomings, the aim of this study is to design a new layer casting system which contains an elevating mechanism, a layer casting mechanism, and a slurry feeding mechanism. The wedge theory was applied to design an elevating mechanism which eliminated the vibration during layer casting.
The error of 30μm positioning was -16μm and the repeat accuracy was no greater than 28.4μm. The vibration amplitude was reduced to 0.76μm and the ripple of the layer was improved.
The new slurry feeding mechanism eliminated the inconvenience of operation. The slurry feeing could be control precisely. Therefore, the consuming of slurry was more economical. Under the prerequisite of no cracks, the improved layer casting system was employed to study the Increase casting speed or reduce the layer thickness to reduced infiltration.

並列關鍵字

Rapid Prototyping ； layer paving ； lift mechanism ； feeding

參考文獻

[20] 彭冠偉，塑膠漿料快速原型系統之開發，碩士論文，國立台北科技大學機電整合研究所，台北，2008。

[14] 劉川豪，陶殼模快速原型系統自動化，碩士論文，國立台北科技大學機電整合研究所，2006。

[3] 黃柏豪，快速原型機新式鋪層系統與陶瓷雷射膠化法製程設備之研發，碩士論文，國立台北科技大學機電整合研究所，2007。

[2] 郭朝輝，陶殼模快速原型機鋪層系統之改善，碩士論文，國立台北科技大學機電整合研究所，2007。

[16] 林文祥，陶瓷雷射熔結快速原型機之研發，國立台北科技大學製造科技研究所，2003。