封閉圖形路徑劃線切割玻璃技術之開發

Abstract

板狀玻璃製品如民生用的鏡子或是車用後視鏡，隨著新興國家的汽車銷售量大增，連帶汽車相關產品需求也隨之成長，車用後視鏡即是其中之一。目前製程通常是從板狀母材中劃線切割出所設計的封閉圖形產品，切割後往往需要再經由人工的按壓及剪片，方能獲得成品。人工按壓及剪片需要一定的經驗，效率及良率不穩定，且長期下來對工作者造成手部傷害，面對大量的產品需求且國際市場競爭激烈，改善此製程使其自動化，攸關於國內廠商的競爭力，是一項很重要的工作。本研究提出一方法讓成品不需經人工按壓及剪片即可脫離母材，利用自行設計之振動輔助機構進行劃線切割來提升中央裂紋深度，並搭配輔助切割道讓成品內部殘留應力釋放，輔助切割道路徑設計在圓弧處外0.3 mm往各角落劃出，最後再以自行設計之輔助裂片平台提供一表面張應力加速殘留應力釋放且將成品自動脫離母材，壓力的部分先以Ansys workbench來模擬。而輔助裂片平台依照相同概念分別針對普通鏡面用之三軸平面玻璃切割機與車用後視鏡之四軸玻璃切割機進行設計。 經由使用三軸平面玻璃切割機進行2 mm厚的普通鏡面用玻璃測試，結果顯示刀輪外徑∅2.5 mm、刀輪角度150°、直線劃線速度300 mm/s、圓弧半徑15 mm之劃線速度120 mm/s、4道輔助切割道次以及利用模擬來決定輔助裂片平台壓力1 kgf/cm2，另外再搭配正弦波、頻率900 Hz、振幅±8μm之振動輔助，可順利將成品自動脫離母材，且正反兩面均擁有良好的表面品質；在車用後視鏡玻璃切割製程上，使裂片過程省去人工的部分，且在搭配正弦波、頻率400 Hz、振幅±8μm之振動輔助可將表面崩落量(chipping)降至廠商所訂制的標準規範200μm以內。

Glass plate products such as mirror or rear-mirror glass are produced by closed shape scribing form base material. The economic rise of emerging countries, car sales is a clear upward trend. With the growth of car sales, the demand of the automotive related products will increase, rear- mirror glass is one of them. We always need to apply extra artificial pressing and cutting to get a finished product after scribing the closed shape path on glass. However, the pressing and cutting require a lot of experience, and may cause hand injury for the workers, not to mention the unstable efficiency. To meet the demands on large quantity products, it is necessary to improve this process. This study proposes a method to make the rear-mirror glass fall out from the base material without artificially pressing and cutting. This method utilize vibration assistant scribing process to deepen the median crack depth, and with assistant scribing line which free from residual stress on interior finished product. The assistant scribing line path design on the outer of arc about 0.3 mm and scribe out to corner. And then, use assistant separation platform which can apply pressure to make the finished product fall out from the base material. We use the ansys workbench to simulate air output press, and glass surface will be a tensile stress state. So it can make the residual stress release. And according the same concept to design the assistant separation platform, for the three axis and four axis glass scribing machine. By use the three-axis flat glass scribing machine for testing and the results show that we can get good surface quality and make the mirror glass fall out form the base material automatically when we set parameters as followed : cutter wheel outer diameter is ∅2.5 mm, the scribing wheel tip angle is 150°, line scribing speed is 300 mm/s, arc scribing speed is 120 mm/s with 15 mm radius, 4 assistant scribing lines and air pressure of the assistant separation platform is 1 kgf /cm2, and vibration assistant with sine wave, frequency is 900 Hz, amplitude is ±8 μm . Follow the assistant scribing line and assistant separation platform approach can also be applied to spherical shaped axis CNC glass cutting machine in rear-mirror glass scribing process, without artificial separation process with vibration assistant with sine wave, frequency is 400 Hz, amplitude is ±8 μm make chipping less than 200μm which is standard specification for manufacturers.