臺灣博碩士論文加值系統

最新建造模具冷卻流道的製程趨勢是使用金屬積層製造(AM)技術，而積層製造的工件表面不盡理想，尤其是在流道燒結的屋頂有未完全熔融金屬形成明顯的接合線，這些未完全熔融的金屬在表面呈現顆粒狀，使表面粗糙度上升。AM能製備非常複雜的異型內流道，但至今尚無傳統機械加工法能處理其表面修整工作。為此，本文提出利用放電加工修整模具內異型水路表面，採創新設計引導機構，包含引導輪機構組、導引線張力調整機構、創新的電極設計與前後導引串珠設計；並採小線段逼近彎弧形式引導電極，以確保修整電極能依順彎折流道行走放電。實驗規畫採紅銅作為電極材料並設計電極為圓球與短錐狀，工件為EOS金屬3D列印機燒結ASSAB公司的CORRAX AM粉末，工件設計採三種內徑10mm之異型冷卻流道分別為30mm長直流道、150度彎折流道與1/4圓弧流道。初步實驗以測試電極形式與導引機構在流道的可加工性與調查適用之放電加工參數，其次分別進行所設計工件形式之放電加工表面修整。經實驗結果表示，本方法能完全修整30mm直流道，流道孔徑尺寸最大為10.856mm，最小為9.858mm，經放電加工後表面輪廓修整為平坦均勻圓管狀的表面，且出入口錐度小至0.038/30。表面粗糙度從未修整前的為7.8~26.4µm，修整至最佳粗糙度降低至5.9µm。。150度彎折流道的孔徑因電極偏擺導致擴孔最大孔徑達到12.546mm、最小值為10.674mm。表面輪廓因電極進給時近似三角形跳動型態的影響，形成連續多節的加工痕，再更改靠近電極梭之前、後導引球設計與新增電源線收緊棘輪機構後，已改善電極串的非線性運動與多節狀痕跡，且能修整全長達43mm；最佳表面粗糙度則達5.984µm。1/4圓弧流道，孔徑擴孔最大達到13.63mm、最小則為10.766mm；最佳表面粗糙度達到了4.201µm；最長修整長度可達31mm，但因線張力作用使外側彎道部分尚未能完成修整。

Novel technologies for building mold conformal cooling channels use metal laminate manufacturing (Additive Manufacture, AM) and the surface quality of such an AM metal is not good. Especially, the sintered roof of the channel often remains a joint boundary formed by incompletely molten metal powders. These exhibits large particles, which greatly increases the surface roughness. Moreover, the conformal channel may be very complicated made by AM that there are no conventional means to deal with its surface trimming. This research proposes an innovative electrical discharge machining (EDM) mechanism to process the surface of the inner channel of the mold and adopts a new string-guide mechanism, including a guide-wheel set, a wire tension adjustment mechanism, an innovative electrode design associated with the front and rear guide beads. The designed electrode ball and short shuttle are aimed at ensuring that the electrode and the string of supporting beads can run smoothly along the curved path with short line segments in conducting EDM process.
The special electrode uses copper as the EDM tool, three types of the workpiece are obtained from an EOS 3D printer with ASSAB's AM CORRAX powder. The workpiece design simulates a conformal channel with an inner diameter of 10mm, which are 30mm straight channel, a 150∘bent channel, and a 1/4 circular arc channel. The initial experiments are to test the EDM machinability of electrodes and guiding mechanisms in the channel and to investigate the applicable operation parameters for EDM trimming. As a result, this method can completely trim 30mm long straight channel, the EDM expansion inner diameter is from 9.858mm to 10.856mm. The EDM effectively trims the contour into a flat and evenly tube, and the taper of the straight channel is as small as 0.038/30 from the entrance to exit. After EDM trimming, the surface roughness is reduced from original Ra 26.4µm to 5.9µm on roof surface. However, the inner diameter is expanded to a range of 10.674mm and 12.546mm for the 150∘bent channel, due to the beating and stumbling of electrode motion. Due to some triangular motion and stumbling of tool electrode, the inner surface of bent path reveals succeeded slubs contour similar to bamboo joints. But it is improved by new electrode beads and a ratchet at rear power core. The better surface roughness of is 5.984µm, and the trimming length reaches 43 mm for the thorough channel length. The inner diameter of 1/4 arc channel is expanded to the range from 10.766mm to 13.63mm. Its best surface roughness reaches 4.201µm and the longest trimming length reaches 31mm, but the trimming of some outer bank has not yet been completely finished due to wire tension.
The special electrode uses copper as the EDM material, three forms of the workpiece are obtained from an EOS 3D printer with ASSAB's AM CORRAX powder. The workpiece design simulates a conformal channel with an inner diameter of 10mm, which are 30mm straight channel, a 150∘bent channel, and a 1/4 circular arc channel. The initial experiments are to test the EDM machinability of electrodes and guiding mechanisms in the channel and to investigate the applicable operation parameters for EDM trimming. As a result, this method can completely trim 30mm long straight channel, the EDM expansion inner diameter is from 9.858mm to 10.856mm. The EDM effectively trims the contour into a flat and evenly tube, and the taper of the straight channel is as small as 0.038/30 from the entrance to exit. After EDM trimming, the surface roughness is reduced from original Ra 26.4µm to 5.9µm. However, the inner diameter is expanded to a range of 10.868mm and 12.546mm for the 150∘bent channel, due to the beating and stumbling of electrode motion. Due to some triangular motion and stumbling of tool electrode, the inner surface of bent path reveals succeeded slubs contour similar to bamboo joints. But it is improved by new electrode beads and a ratchet at rear power core. The better surface roughness of is 5.984µm, and the trimming length reaches 43 mm for the thorough channel length. The inner diameter of 1/4 arc channel is from 10.766mm to 13.63mm. Its best surface roughness reaches 4.201µm and the longest trimming length reached 31mm, but the trimming of the outer bank has not yet been completed finished due to wire tension.

摘 要 I
ABSTRACT II
致謝 IV
目錄 V
表目錄 VIII
圖目錄 X
符號說明 XVII
第1章 緒論 1
1.1 前言 1
1.2 文獻回顧 2
1.3 研究動機 12
1.4 論文架構 13
第2章 加工原理 14
2.1 放電加工 14
2.1.1 放電加工原理 14
2.1.2 放電加工去除機制 15
2.1.3 放電加工參數 16
2.2 積層製造原理 18
2.3 放電加工應用於隨形彎折流道加工 19
2.4 放電加工修整金屬積層模仁異型流道構想 20
第3章 實驗設備與實驗裝置、流程設計 22
3.1 實驗設備 22
3.1.1 EOS金屬3D列印機 22
3.1.2 放電加工機 23
3.1.3 光固化3D列印機 24
3.1.4 示波器 25
3.1.5 電流探測棒 25
3.1.6 差動探測棒 27
3.1.7 張力計 28
3.1.8 表面3D輪廓量測儀 29
3.1.9 表面粗度儀 30
3.1.10 表面輪廓儀 31
3.2 實驗材料 32
3.2.1 電極 32
3.2.2 工件 33
3.3 實驗裝置設計 35
3.3.1 放電加工機與引導裝置機構設計 35
3.3.2 導輪組、調整機構與線張力調整機構 37
3.3.3 電源線與前導引線 40
3.3.4 電極設計 42
3.3.5 工件設計 45
3.4 實驗流程 49
第4章 內流道EDM參數調查與實驗結果 52
4.1 初步實驗 52
4.1.1 機構測試 52
4.1.2 電極測試 54
4.1.3 前後引導球測試 56
4.2 放電加工參數調查 59
4.3 直流道實驗 69
4.4 150度彎折流道實驗 76
4.5 1/4圓弧流道實驗 82
4.6 小結 86
第5章 加工件品質與討論 87
5.1 輪廓建模與形貌量測 87
5.1.1 直流道 87
5.1.2 150度彎折流道 95
5.1.3 1/4圓弧圓弧流道 102
5.2 表面粗糙度 107
5.2.1 直流道 107
5.2.2 150度彎折流道 112
5.2.1 1/4圓弧圓弧流道 113
5.3 電極消耗之比較 115
5.4 小結 116
第6章 結論 117
參考文獻 119
作者簡歷 121

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